The League Cup champions have won just one win in their last six games in the Premier League, having been held to a goalless draw by Southampton yesterday.
The 30-year-old told the club's website: "It's going to be a difficult game. I think it would have been important to beat Southampton, particularly at home, because we now have two tough games against Chelsea and Manchester City.
"We wanted to get something from the game, but we'll try our best. We know how to beat big teams, we have done it already this season, but at this stage it isn't just about performances, we want results as well.
"[Chelsea] are still fighting for the top four, as well as doing well in the Europa League. We know it will be a very difficult game, but we have beaten them before."
Swansea sit ninth in the Premier League table.