Middlesbrough captain Grant Leadbitter will miss the start of the Premier League season with a hernia problem.
The 30-year-old helped the Teesside outfit finish second in the Championship and gain promotion to the top flight, despite needing painkilling injections for the last two months of the campaign.
Leadbitter's subsequent hernia operation was a success, but the club revealed that the injury was more serious than initially thought, meaning that he will miss the opening games of Boro's return to the top flight.
Left-back James Husband and defender Daniel Ayala are also injury worries for the club, with Husband waiting for an operation on a dislocated shoulder.