Who could replace Bradley Walsh and Tosin Cole in Doctor Who?

"It’s been an honour to work on such a cultural institution with fans across the world," added Cole.

"The people like me on the screen come and go, but it’s the people behind the scenes and the fans that will always be there keeping the Doctor Who world alive and exciting."

Now we have to wonder, what's next? Mandip Gill's Yaz is set to continue travelling with Jodie Whittaker in the upcoming season 13, so the Doctor won't be completely alone, but Walsh and Cole's exit does raise a key question - will a new companion (or two) take their place in the TARDIS?

While it's possible Whittaker and Gill could bring the series back to the modern era's usual one-Doctor-one-companion dynamic, it also feels a little drastic to reduce the main cast from four to two, and we wouldn't be surprised if at least one new traveller isn't waiting in the wings to join the action.

So which new actors could join the "fam"? Could we expect some familiar faces from recent episodes, or complete newcomers? And how would they fit into the Doctor Who dynamic?

In a list carefully selected by RadioTimes.com editors, we’ve assembled a few runners and riders below…

John Barrowman as Captain Jack Harkness

Of course, we now know that John Barrowman's immortal Time Agent will be back in Revolution of the Daleks, with the former Ninth and Tenth Doctor companion teaming up with Graham, Ryan and Yaz to battle the Dalek threat.

But could this just be the precursor to a longer spot in the series? Barrowman has played a recurring companion before, after all – he’s in the final five episodes of the revived 2005 series taking part in different adventures – and he remains a popular character with fans.

Then again, Barrowman has never appeared as a regular companion alongside the Doctor, and it’s possible Captain Jack works better as an occasional guest rather than a permanent TARDIS resident. We’ve never had anyone other that a present-day human act as a main companion in the revived series – would a 51st-Century expert in extra-terrestrials slightly cramp the Doctor’s style?

Considering that Barrowman is also currently in Palm Springs while season 13 films in South Wales, we don’t see this happening. Especially when Jack will presumably be too busy reviving Torchwood to travel with the Doctor anyway…

Joana Borja as Gabriella Camara

It’s possible that we could also look a little closer to home for a new TARDIS team member – series 12’s Joana Borja, who cropped up in the sixth episode Praxeus as travel vlogger Gabriella Camara.

When the episode aired, some fans suggested that Borja’s character would actually make a good companion further down the line, so could that approach be possible? Doctor Who companions have been sourced from one-off roles before, after all, with Catherine Tate’s Donna Noble only intended for a single Christmas adventure before rejoining the series a year later as a full-blown companion.

Of course, Tate was a huge UK star already when cast in Doctor Who, and her character was still the second lead during her guest role in The Runaway Bride, so it’s not quite the same – Borja was one guest actor among many. But Doctor Who has also curated talent from the background before, casting Freema Agyeman as Martha Jones after she impressed playing a small guest role in 2006’s Army of Ghosts/Doomsday.

If Borja did come back, there’d be a natural arc for Gabriella – she’s travelled the world, why not see more – so who knows? There’s certainly a possibility she could make a comeback.

However, given that both Walsh and Cole are leaving, it seems far more likely that we’re looking at one or more male companions joining the team, in which case we might need to take a look at some other returning candidates…

Warren Brown as Jake Willis

We’re not going too far for this one – like Gabriella, Jake was a one-episode character in Pete McTighe and Chris Chibnall’s Praxeus, who played a significant part in the Doctor’s battle to stop a deadly pathogen.

An ex-police officer with intimacy issues, Jake ended the episode a hero and saved his ex-husband (below) while flying a spaceship, before the Doctor saved him and sent him off to “travel.”

Jake was pretty handy in a crisis, so maybe Brown could make a comeback – and if they wanted two new companions to replace Cole and Walsh, maybe he could bring his other half along too?

Matthew McNulty as Adam Lang

Another Praxeus alumnus, Adam was an astronaut – so not a bad candidate for time-and-space travel – and arguably didn’t get enough of a showcase within the episode runtime. Teaming up with Jake, we could definitely see him fitting in with Yaz and the Doctor.

With all these examples said and done, however, it’s worth noting that Doctor Who usually opts to cast newcomers to the series in its top roles – and if we are looking for male companions to replace Cole and Walsh, there are a lot of actors who could make the grade.

Alexander Vlahos

Merlin and Versailles star Vlahos has been open that he’d be interested in a Doctor Who role, telling us in 2017 that it’d be a “dream job” for him to join the series.

“I’ve got to stop talking about it, I think,” Vlahos told RadioTimes.com, clearly afraid of jinxing himself. “I think if I stop talking about it it’ll happen. I think if I continue to blab on and say that I want to play it, it’s never going to happen.

Sure, he’s always said he’d play the Doctor rather than a companion, but we’re sure he could be persuaded…

“Honestly it’s my dream job and I keep saying to my agent, 'If I ever played the Doctor I think I might quit acting after that,'" he told us.

"So I think maybe she’s not putting me up for it because she wants me to continue working."

If enthusiasm alone were enough to get the job, it’d be his.

Chance Perdomo

British actor Perdomo has been quietly amassing some impressive roles over the last few years, bagging a BAFTA nomination for BBC Three’s Killed by My Debt before joining the main cast of Netflix series The Chilling Adventures of Sabrina.

With a relatively low UK profile, experience with sci-fi/fantasy roles and a lot of natural ability (his Sabrina character Ambrose was written for him after he impressed the showrunner in a previous audition), Perdomo could be a great fit for Doctor Who – and with Sabrina now cancelled, he may have a bit of spare time to fit in with Who's filming schedule...

Edward Bluemel

Another actor with a bit of experience with supernatural forces, Bluemel’s big break came when he was cast as vampire Marcus in Sky One’s A Discovery of Witches, before racking up roles in Sex Education and Killing Eve.

Used to acting with special effects? Tick. Bit of international notoriety? Also tick. The TARDIS team could do a lot worse.

Anthony Welsh

You may have spotted Welsh recently in a spate of TV appearances – Pure, Brassic, The Trial of Christine Keeler – having previously appeared in films like Starred Up, Journeyman and The Girl With All the Gifts.

A real up-and-comer, it’s not hard to see him filling the void in the team – and at 36, he could offer a slightly different dynamic to the younger companions of the team (assuming he didn’t just play younger).

Nabhaan Rizwan

Rizwan has managed to explode onto the acting scene over the last couple of years, scoring his first lead role in BBC undercover drama Informer before appearing in the likes of The Accident and 1917 in the months following.

Currently, he stars in banking drama Industry and will soon appear in an adaptation of acclaimed apocalypse novel Station Eleven – so could a Doctor Who role also be on the cards? Given his natural charisma, he’d certainly be an asset.

Micheal Ward

Known for appearances in Top Boy and The A Word, Ward recently won a BAFTA Rising Star award for his turn in the critically-acclaimed Blue Story, putting him on plenty of radars early in his career.

Arguably, his future might lie on the silver screen rather than TV but if he’s looking to take a leap into the unknown, the Doctor Who team would be lucky to have him.

Will Mellor

Once rumoured to play the Doctor, Two Pints of Lager and a Packet of Crisps’ Will Mellor could bring his comedy and dramatic chops to the fore as a Doctor Who companion, filling a similar role to the departing Walsh.

Like Walsh, Mellor could also bring a little more maturity to the TARDIS team, if head writer Chris Chibnall wants to continue having companions who aren’t solely in their 20s, and he also has the advantage of having worked with Chibnall before on Broadchurch (like recent Who stars Lenny Henry, Julie Hesmondhalgh and, of course, Jodie Whittaker).

We'd say that all puts him right in the frame.

Larry Lamb

Similarly straddling the comedy/drama divide is Gavin & Stacey and EastEnders star Lamb. Doctor Who currently has a full crop of ex-soap stars among the companions – Mandip Gill and Tosin Cole were in Hollyoaks, while Bradley Walsh played a key role in Coronation Street – so it’s not out of the question that they’d dip into that pool again.

Meanwhile, like Mellor, Lamb offers the kind of broad appeal previously brought to the series by Walsh. And who wouldn't want to see Mick Shipman in the TARDIS?

Paul Mescal

OK, OK, look – it’s not that likely that on the heels of his critically-acclaimed, cultural conversation-dominating turn in BBC Three’s Normal People, Paul Mescal would decide his next big step would be to lock himself into Doctor Who’s intense 10-month filming schedule. And to be honest, he’s probably already getting glitzier offers from around the globe.

But he’s on our list for a reason – because if anyone can make “reacting to CGI monsters” look soulful and moving, it’s him. Especially if he brings the chain.

Masali Baduza

Of course, it’s also possible we’re making too many assumptions in looking for a new male actor to join the TARDIS team, especially if more than one person is joining Whittaker and Gill in the TARDIS.

With that in mind, if they were looking for a female actor it’s not hard to imagine Noughts and Crosses’ Baduza – who had only a handful of credits to her name before playing the lead role of Sephy – crossing over into another big BBC series and delivering another terrific performance.

Or, finally… someone we’d never expect

When a new Doctor is coming to Doctor Who you can make a few educated guesses, but when it comes to companions it’s much harder to pick who’s next in line. After all, before she was revealed in 2016 who could have guessed Pearl Mackie (who had next to no screen credits at the time) would be Peter Capaldi’s new co-star?

And what about Tosin Cole and Mandip Gill before they were announced? No-one saw that coming. Sure, Bradley Walsh’s involvement had leaked out, but in casting newcomers Doctor Who can often keep us surprised.

It’s also worth noting that with filming only just beginning, it could still be a while before any new companions are announced – assuming there aren't any major leaks – so it’s possible we’ll be waiting a long time to see if any of our guesses were even close to the truth.

In other words, this speculation has only just begun. Buckle in, folks…

Doctor Who: Revolution of the Daleks comes to BBC One on New Year's Day. Want something else to watch? Check out our full TV Guide.