Branislav Ivanovic is a doubt for Chelsea's next game against Aston Villa after Roberto Di Matteo confirmed he intends to continue rotating his squad.
Serbian defender Ivanovic limped out of last week's defeat at Manchester City with a thigh injury and he subsequently missed the 0-0 draw at home with Tottenham Hotspur.
The right-back failed a fitness test prior to Tuesday's UEFA Champions League win over Benfica and Di Matteo will keep a watching brief over Ivanovic ahead of Saturday's trip to Villa Park.
"We will need to see how he recovers in the next few days, at the moment he's doubtful for the weekend, but we hope he can recover as soon as possible," said Di Matteo.
Ivanovic's absence against Benfica provided Paulo Ferreira with only his third start of the season, while Salomon Kalou scored the only goal at the Estadio da Luz.
Di Matteo also sprang a surprise by leaving Michael Essien, Didier Drogba and Frank Lampard out of his starting line-up for the first leg of the quarter-final tie.
However, Di Matteo insists keeping the squad fresh will be important as he looks to give those players who were largely overlooked by Andre Villas-Boas a chance to impress.
He added: "I'm involving everybody that is in the squad, rotating.
"We'll need everybody until the end of the season. We cannot play with just 11 players.
"You'll see other players who have maybe played a little less in the past playing more of a role in the future.
"It's just impossible for us to play every three days and reach the fitness levels needed to win games."