Two years ago he returned to Old Trafford for a then-world record transfer fee of £89million.
"The only truth is that I made the decision for him not to be second captain any more but there is no fallout, no problem", Mourinho said.
Pogba and Mourinho are believed to have exchanged words at United's training ground after the manager became concerned by an Instagram post that Pogba sent after the Carabao Cup defeat to Derby County.
The Portuguese manager is expecting the Old Trafford hierarchy to back him the way they used to stand with Sir Alex Ferguson in his battles with player power back in the day, according to The Sun.
There have been reports this week that suggested a fresh fall-out between the pair, and Mourinho confirmed on Tuesday that Pogba is no longer the club's vice-captain.More news: Mourinho: Pogba will never captain United again
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But Mourinho is said to have accepted Pogba's explanation as to why it was uploaded after United were knocked out, with WI-FI issues apparently to blame for the delayed post.
The Irish Independent says a bubbly Pogba was filmed running out to training but, after high-fiving assistant coach Michael Carrick, the midfielder stopped abruptly when Mourinho appeared to ask the player if he was "happy" United lost after they exchanged a cursory handshake. I think Mourinho has done more than Pogba in that time.
The Guinea worldwide who began his career with La Liga side Celta Vigo has previously played in leagues at various levels in leagues across England, Scotland ant Italy. I can assure Man Utd fans, you won't.
It followed comments made by Pogba after last weekend's disappointing home draw against Wolves where he moaned about his side's defensive tactics. He's not as good as he thinks he is.