Southend United expect Steven Hammell to be out of the team for six weeks.
Hammell suffered an ankle injury during last week's friendly with Crawley, with the club initially fearing the defender had broken his leg.
Once those concerns were allayed, the League One side expected Hammell to miss the opening month of the new season.
But after his foot flared up on Monday, Hammell has undergone further scans to ascertain the full extent of the damage.
With the results back in, Southend predict the former Motherwell man will be out until the end of September.
Physio John Stannard told the club's official website: "With no other problems he will probably return in about six weeks.