Swansea defender Angel Rangel could miss the start of the new season after undergoing surgery.
The Spanish full-back was sent for an operation on Tuesday to repair a long-standing hernia problem and could be sidelined for up to six weeks.
Swansea begin their Championship campaign in just over five weeks against Charlton on 9th August, while they also face Brentford in the Carling Cup the following Tuesday.
Striker Jason Scotland is also set to go under the knife due to an abdominal injury but should not be out for so long.
Manager Roberto Martinez is disappointed with the news on both players as Swansea begin their pre-season training.
"We tried some conservative treatment on Angel and hoped it would heal over the summer," Martinez told the South Wales Echo.
"But we're not happy with it and he's had an op that will rule him out for between four and six weeks.
"We will have to see whether he recovers in time for the start of the season, but Angel's a fit boy and I'm optimistic he'll be back pretty quickly.
"Jason's is a shorter recovery period. He has a muscle strain and should be out for around two weeks, so he'll definitely come on the pre-season trip to Spain."
Martinez was happy with the overall condition of his squad, adding: "They have come back in fantastic shape.
"The enthusiasm among the players is obvious. You can feel the competitive edge already and the group look hungry."