Chelsea boss Frank Lampard has been praised for convincing Chelsea owner Roman Abramovich to sign Edouard Mendy from Rennes.
The Senegal international is yet to concede a goal in the Premier League and Champions League so far.
Tony Cascarino told talkSPORT: “Obviously if you are a manager and have decided you can’t continue this way, I need to wash my hands with this particular goalkeeper Kepa and move away.
“You’ve convinced the owners you’ve convinced Petr Cech who is a goalkeeper and had to deal with all those issues with Frank I’m sure. It’s been very important. He’s (Mendy) come in and it feels quite settled very quickly.
“It makes everyone a bit edgy and all the jokes come out and you don’t have as much trust. These moments are defining in football because they can get you three points or a draw or a defeat. So the goalkeeper, Kepa was playing to a very poor level.
“You need those things as a manager, you need those players to take responsibility and perform to a level that’s the standard required for Chelsea.”