Chelsea striker Diego Costa will play against Manchester United, providing he trains in full on Saturday.
The Spain international, 26, spent a night in hospital earlier this week with a viral infection.
He has been recovering at home but ahead of Sunday's game at Old Trafford, Blues boss Jose Mourinho said: "I want to play Diego if he is ready.
"He has to show on Saturday in training that he's capable of playing. If he's ready to play, he plays."
|Costa's Chelsea campaign|
|Burnley 1-3 Chelsea - scored, booked|
|Chelsea 2-0 Leicester - scored|
|Everton 3-6 Chelsea - scored two, booked|
|Chelsea 4-2 Swansea - scored hat-trick|
|Chelsea 1-1 Schalke - failed to score|
|Man City 1-1 Chelsea - booked|
|Chelsea 2-1 Bolton - failed to score|
|Chelsea 3-0 Aston Villa - scored|
|Sporting Lisbon 0-1 Chelsea - failed to score|
|Chelsea 2-0 Arsenal - scored|
The frontman has scored nine goals in seven Premier League games despite a persistent hamstring problem, but has missed the last two matches.
He was then laid low by a virus and barred from attending the club's training ground in Surrey.
"Everything has happened to him and being ill obviously didn't help his recovery process because we didn't want him at Cobham," said Mourinho. "The medical staff were going to meet him at his house."
Asked what Costa needed to do to be involved against United, Mourinho added: "He has to train without any limitations, to make a complete training session with the other guys, without any kind of protection."
John Mikel Obi, Ramires and Andre Schurrle could all return after injury and illness, but Cesar Azpilicueta begins a three-match suspension after being sent-off at Crystal Palace.