Chelsea defender Cesar Azpiliceta feels their heavy schedule is catching up with them.
With extra games in the UEFA Super Cup, World Club Cup and Europa League - the Blues find themselves with a season 15 games longer than FA Cup semi-final opponents Manchester City.
"We played three days ago in Moscow - so it is the reality. But we are professional: we try to do our best to prepare for the game the best that we can. But after all - it is a game, and it is normal that we feel a bit more tired than the other team.
"We did this season with two semi-finals, also the Capital One Cup, so it is true that we have played a lot of games."