Frank Lampard has confirmed that Chelsea youngster Callum Hudson-Odoi has suffered a setback in his recovery from injury.
The England international has been missing since early February and will now have to undergo another scan following a recurrence of the problem during his first training session back with the Chelsea squad.
Blues boss Lampard is short on a number of key players and, while both Ruben Loftus-Cheek and Christian Pulisic were involved in an in-house match between the Chelsea squad on Friday, both are short of match fitness.
Asked about Hudson-Odoi's situation, Lampard said: "He had a re-injury, yesterday. We're having a scan on him this afternoon. So he will be longer than expected.
"It's tough, he wasn't rushed back, we had all the signs that he was fit to train. Then he re-injured it on his first training session with us.
"So it's frustrating for him definitely, a young boy who's keen to play as you'd expect. And it's frustrating because it's another injury to us.
"It hasn't been spoken about that much, but we've had probably the worst injury list of certainly the top group of the table I think, lots of numbers injured, important players injured, [N'Golo] Kante, Loftus-Cheek etc.
"We started the season that way and it's happened again in the middle of the season and we're working against that to try to get the best results."
Lampard will also be without Mateo Kovacic this weekend after both he and Willian were forced off with Achillies problems during Tuesday night's win over Liverpool in the FA Cup fifth round. The Brazilian will have to pass a late fitness test if he is to be involved against Everton on Sunday.
"Kovacic isn't fit, his Achilles injury will take him out of the weekend, but hopefully it will not be long after that," said Lampard.
"And Willian we are assessing, he's a question-mark for Sunday."
