France midfielder Pogba was signed by Mourinho in 2016 for a then-world record transfer fee of £89million. He has scored 12 goals in 74 appearances since arriving at Old Trafford.
Pogba started the current campaign in fine form but was sidelined for over two months at the end of 2017 after suffering a hamstring injury in the Champions League clash against Basel.
His influence for United has not been the same in recent weeks and he was benched earlier in the month for the Premier League fixture against Huddersfield Town.
The 24-year-old was then taken off during United’s shock defeat to Newcastle United last weekend and Redknapp feels Mourinho is failing to maximise his potential.
‘I can’t believe we’ve got to this situation so quickly, because when he got sent off against Arsenal, everyone was rolling out the stats that Manchester United can’t play without him,’ he told Sky Sports.
‘Everyone said that he was indispensable but now everyone is saying he’s useless again. When things are good, he’s the best player in the world. And now because of his price tag he’s getting slaughtered.
‘I think Mourinho has a big responsibility with him, it’s his job. Everyone expects him to be this big confident player, but I think deep down he needs to be loved.
‘Taking him off against Tottenham, that’s not how you’re going to get the best out of him. You can see at Newcastle, his confidence was really low.
‘I’m not saying you need to pander to him but I don’t see a situation where Pep Guardiola would do that. If he was playing at Man City, he would be one of their star performers.
The former Liverpool and England midfielder added: ‘I just don’t think that Jose Mourinho gets the best out of him. Pep’s the sort of manager who would bring him on, but with Mourinho it almost feels like he’s taking him on.
‘This isn’t a kid he’s dealing with, he’s one of the biggest assets in world football. Mourinho is asking for a war now with current players.
‘With Pogba’s power in that dressing room, Mourinho has got to be very careful. I don’t see the benefit in upsetting one of your star players.’