The veteran presenter was struck down by flu earlier this week, and will therefore miss tonight's live show. Claudia Winkleman will stand-in for him.
Although the BBC have said they expect him to be back on air next week, a tabloid report today suggests that he wants to be away for longer - and that bosses are growing concerned.
A show source has told The Sun that "the long hours leave him exhausted".
Sir Bruce Forsyth and Tess Daly on the red carpet (WENN)
They said: "Bruce is a national institution but he is 85. When you're 85, you can't just pop a few tablets and get on with things like people in their 30s or 40s."
The alleged insider added: "It feels like he's on borrowed time."
However, speaking on Alan Carr: Chatty Man last night, Tess Daly slammed those who accuse Brucie of being too old to carry on with the demands of the ballroom competition.
“How dare they? Bruce has been in showbusiness for 70 years. He’s the consummate pro," she said. “His posture is incredible, and he dances across the floor and exercises morning and night.”
A spokesman for the man himself said: “He got the flu on Tuesday and hasn’t recovered yet. It’s nothing terribly serious and we are very hopeful he will be doing the show next week."
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