The TARDIS will be a bit less crowded in 2021.
The Daily Mirror is reporting that Doctor Who co-stars Bradley Walsh and Tosin Cole will exit the series after the upcoming 2020 holiday special, "Revolution of the Daleks". Although their respective characters, Graham O'Brien and Ryan Sinclair, will be written out of the series, fellow companion Yasmin "Yaz" Khan (Mandip Gill) will return for Series 13 along with star Jodie Whittaker.
According to the article, "Revolution of the Daleks" has been filmed, but the specific nature of Ryan and Graham's departure is a closely-guarded secret. One of the Daily Mirror's sources remarked, "Two years is a long time in the world of Doctor Who. Yaz will be back but Christmas will be the last outing for Ryan and Graham."
However, fans of the characters may have hope for seeing them again. The Radio Times has additional word from their sources that Walsh and Cole could continue "to make sporadic appearances in Doctor Who despite not being part of the main cast." This, as their article suggests, could be similar to previous Doctor Who companions that returned to the series, such as Rose Tyler (Billie Piper) or Martha Jones (Freeman Agyeman).
Walsh, 59, currently hosts an ITV travel show with son Barney called Breaking Dad and will continue to host quiz show The Chase. Cole, 27, has already landed a role in the upcoming AMC courtroom drama series 61st Street.
Doctor Who is scheduled to return for "Revolution of the Daleks" sometime between Christmas 2020 and New Year's, followed by Series 13 sometime in Autumn 2021.