"He's certainly playing a lot better. His form has been consistent. But it was always tight for us whether Richard was in or not," said Kerr of Dunne's first call-up since last March.
The 25-year-old Manchester City defender will earn his 21st cap if he figures against France on Saturday week.
Midfielders Matt Holland and Liam Miller's inclusions have boosted Kerr also, and he is confident both can be fit for the Paris clash.
"Matt hasn’t played since the first game of the season. He played in a reserve match last week and he played again on Tuesday night. This must be the longest spell he’s ever been out of competitive games," added Kerr.
"He has an extraordinary record for continuous matches as we all know and I think he’s always in good shape.
"Maybe he’ll be involved this weekend (against Arsenal). If not, we still have a week and a half to the first match. There’s plenty of opportunity for him to sharpen up.
"Liam? We’ll see what happens with him. If he wasn’t match sharp, I don't think Manchester United would have used him against Spurs or in the European match during the week. I’ll be happy enough that Liam is in good nick."