The fact Raiola, who was in the north-west yesterday, is trying so hard will only increase the belief the players wants out of United after just two years.
"I think the World Cup is the flawless habitat for a player like him to give [their] best", Mourinho said.
As reported by Gianluca Di Marzio, Barca have offered €50 million for the Frenchman, plus centreback Yerry Mina and midfielder Andre Gomes.
Earlier this week, there was talk of Manchester United looking at Mina.
The likes of Harry Maguire, Toby Alderweireld and Jerome Boateng have all been strongly linked with a move to Old Trafford in recent days but there's no guarantee United will sign any of them before the window closes on Thursday night.
The 25-year-old, who lit up the World Cup finals in Russian Federation, has often flattered to deceive since returning to United from Juventus two years ago.
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"Pogba is a great player, who is on another team and we are always very respectful of the players on other teams", he declared. I think the World Cup is the ideal habitat for a player like him to give the best.
'For one month the players are in a closed camp, ' Mourinho explained.
His agent, Mino Raiola, is expected in Manchester this week to negotiate the transfer of Pogba out of Old Trafford.
The Red Devils, therefore, have limited time to acquire a replacement for Pogba and makes any deal before the transfer window in Spain closes on 31 August a near-impossibility. However, the deadline in England is 5pm on Thursday, leaving United little or no time to sign a replacement unless they meant to replace him with new £52m signing Fred.
Pogba's agent, Mino Raiola, is now in England to guide the 25-year-old out of Old Trafford, and negotiations are expected to be fully completed before the window closes next Thursday, according to Mundo Deportivo.
But it seems United have turned down the shockingly-low bid.
However, Mourinho disputed suggestions that it's down to him to get the best out of Pogba. Everton have lined up Mina as a back-up if they can not sign Rojo but face competition from Lyon.