Chelsea right-back Reece James could reportedly be forced to go under the knife with a lingering issue in his right knee.
The 21-year-old has kept the experienced Cesar Azpilicueta out of Frank Lampard's starting lineup this season, with James starting 11 of Chelsea's 13 Premier League matches this term.
James played the full 90 minutes in the Blues' recent defeat to Wolverhampton Wanderers, but the defender is understood to have played through the pain barrier in that game and in the previous loss to Everton.
Now, The Athletic reports that James may have to undergo surgery on his knee problem, although the full extent of the full-back's injury is yet to be determined.
The England international will reportedly have the results of a scan back within the next two days and he has not yet been ruled out of Chelsea's game with West Ham United on Monday.
Hakim Ziyech and Callum Hudson-Odoi are Lampard's only other injury concerns at the moment, but both wingers are expected back within the next couple of weeks.