Jose Mourinho believes 34-year-old Sunderland striker Jermain Defoe could be a target for top clubs should the Black Cats be relegated this season.
Mourinho, who signed Zlatan Ibrahimovic at the same age last summer, is wary of Defoe's threat when United travel to the Stadium of Light on Sunday.
And he doesn't think the forward's birth certificate will count against him should he try to move on in the summer.
'I always say age is not important if your body is below that age.