Tottenham will challenge Arsenal for the signature of Eric Bailly, according to reports.
Bailly suffered the humiliation of being substituted after just 18 minutes by Mourinho against Newcastle last weekend, with midfielder Scott McTominay taking over from the centre-back in defence.
The Daily Star claim Mauricio Pochettino wants Tottenham to move for Bailly should United look to offload the 24-year-old.
Pochettino has long admired Bailly, but it is unclear if United would be open to selling the defender.
United rarely sell to a direct rival and would want to recoup most of the £30million they paid for Bailly in 2016.
Mourinho lured Bailly to United from Villarreal and the defender was the United boss No.1 choice in the heart of the Red Devils defence.
But Baillys stock at United has plummeted this season and his first Premier League start since September ended in disaster against Newcastle.
United were 2-0 down when Bailly was hauled off by Mourinho, and it is unclear where the defender now stands with his manager.
Bailly is thought to be keen on a switch and would be open to remaining in England rather than returning to Spain.