Chelsea defender Branislav Ivanovic has complained about the number of fixtures that his team have played in the last few months.
The Blues, who beat Sparta Prague 1-0 in the first leg of their Europa League last-16 tie on Thursday, host Brentford in an FA Cup fourth-round replay on Sunday.
"We have had a lot of games," Ivanovic told reporters.
"We have played every three days for the last four months. This has made it difficult. Sometimes you're not recovered and don't have a big enough squad.
"All these things affect results, but you have to be stronger. Now we have some time, we can recover and play our games with a better performance."
Chelsea are currently 16 points behind leaders Manchester United in the Premier League table.
