The midfielder felt the Reds were denied a clear penalty when Maynor Figueroa handled a Phil Jones cross in the box but had few complaints about the scoreline.
"We didn't perform," he told MUTV at the DW Stadium. "For a start, our normal passing game wasn't as fluent and we kept giving the ball away. Obviously, you've got to give credit to Wigan - they put us under a lot of pressure, especially early on and credit to them as well.
"They worked hard but that's something we come up against quite a bit [being closed down] so it's not an excuse not to be able to handle that. We just didn't keep the ball like Manchester United usually do. I think we only had one or two shots on goal and that's also disappointing so we have to look at the game and work on it and get ready for Sunday."