Barry refused to use uncertainty over the future of Mancini as an excuse for City's shock defeat.
Barry said: "We are professionals. We can't use something like that as an excuse. We have it not just before this game, but all this season and last season as well.
"What happened today has nothing to do with the speculation.''
Reflecting on the game, Barry added: "It was exactly the sort of game we expected really.
"We knew what sort of game Wigan play and on a pitch like this they can play their football, no matter what the situation is.
"They have got a fight at the bottom of the Premier League but they showed what a good team they are.
"We didn't play our normal passing game, but sometimes that can happen at the end of the season.''