Berbatov has been criticised after his dreadful penalty miss against Everton in the FA Cup semi-final.
“He will be criticised for that because when you pay £30m for a player everyone thinks you should be able to score from a penalty kick,” he said. “But it’s just not as simple as that.
“I don’t see any evidence that he’s tailing off. He had his injury and missed a couple of games, but he came on and did well in the game.
“He did really well. He’s disappointed to miss a penalty, of course. He was upset, but it was a disappointed dressing room.
“You lose in a semi-final – and it’s the first we’ve lost – and that’s not easy to take. Anyone can lose on a penalty kick, I’ve lost many like Sunday.
“I don’t see it as a defining part of my career because anyone can win or lose them.”