How the hell do you know that?
Because it's pure logic from every single perspective there is.
I've maintained this since before the season ended. From a sporting perspective the manager has made it clear that he wants to build a team around Pogba, he's easily one of our best players, if not the best, and he's a key part in us improving as a team and finishing top 4. From a marketing perspective, having finished the season outside the top 4 with no champions league next season, with a rather unknown manager, losing our biggest star would be a huge blow and a rather shit statement about our future. A transfer makes feck all sense to the manager and it makes feck all sense to the higher ups at the club. He's under a long term contract as well.
Another factor is priorities, the number of players we needed to bring in (and we haven't exactly done a great job so far), losing a key first team player and needing to replace one more player would be brutal. It's fecking difficult to successfully integrate half a new first team.
The only uncertainty was how much shit Raiola and Pogba were going to stir up, but it's been surprisingly calm, probably because Real Madrid aren't pushing for a transfer (for a number of reasons). There's also the Euros next season, and he's hardly unprofessional (even though some like to pretend he is). Our current relationship with Real Madrid is shit at best, given how far outside our interest it is to lose Pogba this summer we'd go a long fecking way to tell them to get bent.
We'll offer him a contract extension with a fat wage, and set conditions that allows him to leave next summer for a hefty fee and it'll be a win-win for all parties.