Manchester United defender Eric Bailly was ready to sign for Arsenal this summer.
The London Evening Standard says United informed Bailly he would not be allowed to join Arsenal because they are one of the Red Devils' direct rivals.
Bailly was understood to be on Arsenal's radar at the start of the summer having fallen down the defensive pecking order at Old Trafford.
He did not seal a switch though and remains part of Ole Gunnar Solskjaer's squad as they attempt to challenge for silverware on four fronts.
Bailly was stopped from swapping United red for that of Arsenal due to the fact they are vying for the same league positions and trophies.