Chelsea have played 46 games. Arsenal have been the busiest of Chelsea's top-four rivals having played 41 games, followed by Tottenham and Manchester City (both 38) and Everton (32).
Gary Cahill: "Unfortunately it does take its toll.
"I think if you look back at the start of the season with the spark and the zip we had - I think sometimes a little bit of fatigue plays its part.
"We haven't had a clear week for about 29 weeks and you're expecting to go into games feeling 100 per cent fresh, trying to push on further in all competitions.
"I think at this stage of the season, it's not an excuse, but fatigue has to play a part.
"They (Manchester City) had a clear week and we've had a ridiculous amount of games.
"I think it told. I thought they were a lot fresher and sharper.
"We talked about it afterwards and we have to keep getting on. There's nothing we can do about it.
"It's something that we have got to deal with.
"We've got the two cups and obviously trying to get the Champions League spot.
"That's our aim from now until the end of the season. That's our focus. We have to go again. We are still in that position.
"All three are in our own hands so we need to keep going and plug away and make sure we achieve the goals we want to achieve."