Fletcher, who also scored against Benfica, is adamant Berbatov will come good.
Fletcher said: "He would expect to take a chance like that but the positive thing is he's in there in goalscoring positions. If he does that, then we know that with the quality he's got, he will pick up goals in future.
"Berba is a fantastic player. He's not featured as much as he would like this season but he's got his head down and worked hard in training. He's come in and got his goal and it's a great option for us.
"The manager has four strikers and that's what he needs if we are going to achieve what we want to achieve this season. I'm sure Berba will be a big part of that."