The result leaves Rovers in ninth place and Berg said the quality of the finishing was the key difference between the sides.
"For the first goal, it's possible to stop it before Wood gets the ball," he said. "It's a fantastic strike but we could have done better before that.
"The second goal, we lose the ball in the centre in midfield and again they got a shooting opportunity that he took well. The biggest difference between the teams was the shooting ability."
Josh King made his first appearance off the bench after joining on loan from Manchester United and Berg added: "I think he did okay.
"He doesn't know the players and has hardly trained with us so we had to have a good look at him before he came on.
"He got into some very good positions and had a great effort with his first shot."