Chelsea are sweating on the results of scans on Reece James after he suffered a hamstring injury in training.
Captain James is having the injury assessed after picking up the problem during a session on Wednesday and Chelsea are hoping to discover the extent of the damage in the next 24 hours.
Right back James missed the end of last season with a hamstring injury, sitting out Chelsea's final seven games.
He had returned to fitness ahead of the new season, was named new skipper and started Chelsea's season opener against Liverpool on Sunday.