Sheffield United's record signing Claude Davis will miss the start of the Premiership season, and may not play again until mid-September.
The 27-year-old Jamaican completed his £3 million move from Preston North End at the end of last season, but has been suffering through pre-season with a knee problem.
Tests have now revealed that the defender has knee cartilage damage, and he has consequently been ruled out of action for up to six weeks.
He was forced to limp off in The Blades' stalemate friendly against Notts County at Meadow Lane on Tuesday, and according to Bramall Lane officials he may now require surgery.
The injury could mean a dramatic recall to the starting line-up for veteran centre back Craig Short, after he announced his retirement at the end of last season.
Boss Neil Warnock has offered the 38-year-old a new contract with the club and expects him to return to the squad after his summer holidays.
Chris Lucketti is another option for Warnock, but the South Yorkshire outfit have other injuries as well ahead of their two-match pre-season trip to Holland, with new boys David Sommeil and Mikele Leigertwood both having been on the sick list recently.
United kick off against Sparta Rotterdam on Saturday and then take on ADO Den Haag before the start of the new Premiership season.