The Red Devils boss backed the world's most expensive player to show hie value over the next 12 months.
He endured a disappointing first season back at Old Trafford following his £89m move from Juventus last summer.
Mourinho thinks Pogba is good enough to start for Barcelona or Real Madrid.
But Nicol simply doesn't agree.
He told ESPN FC: "Jose Mourinho is not afraid to open his mouth and say nonsense.
"I'm not suggesting it's nonsense, Paul Pogba's got fantastic ability.
"His ceiling is at the level of all those players he's talking about at Barcelona and Real Madrid, but he's not there yet.
"To come out in pre-season in particular and say that, I mean what is he going to be like when he's fit?
"He can't be 100 per cent fit yet, so what is he going to be like this year?
"Listen, Jose Mourinho is talking up his player, trying to give Pogba confidence which is great, and that's what you expect a manager to do, but I would't look into it too deeply."
