The Frenchman arrived at Old Trafford after finalising his world-record transfer from Juventus this summer.
His performances have left fans frustrated as he hasn’t been able to live up to expectations after his showings in Italy.
Speaking about Mourinho, Carragher claims he should change his side to fit in his new signing.
“But should a manager have to change to fit in one player? If they cost £90m, then the answer is yes.”
Mourinho switched to a 4-3-3 system against Feyenoord on Thursday night after leaving Wayne Rooney out of the travelling squad.
Carragher’s comments to drop Rooney and Mkhitaryan are ridiculous, but a change in tactics is necessary to help Pogba adapt to life in England.
The Portuguese boss will have to switch his tactics heading into the Watford fixture, starting slow against Manchester City and Feyenoord cost his side and he’ll be looking to redeem himself at Vicarage Road.