The Independent says heading out of Old Trafford is likely to be captain Wayne Rooney.
Rooney's influence at the club has drained away this season and he could be moved on.
It's claimed Italian defender Matteo Darmian could also bid farewell to the club.
Meanwhile, for Mourinho a striker is the top priority, although he could now target two after Zlatan Ibrahimovic's lengthy injury layoff.
A new centre-back is also wanted.