Bolton's Stuart Holden is expected to miss another six weeks of action due to a routine procedure on his knee injury.
The USA international sustained the long-term injury in last season's 1-0 defeat to Manchester United at Old Trafford following a challenge by Jonny Evans.
Holden was thought to be closing in on full fitness after playing the full 90 minutes in their recent Carling Cup win at Aston Villa, but he needs more surgery.
Bolton had hoped the operation could be carried out next summer, however, the date has been brought forward for the player's welfare.
"Our prime concern has always been Stuart's welfare and his long-term health and fitness," manager Owen Coyle told the club's official website.
"It was looking likely that the operation could be scheduled for next summer, but after follow-up consultations with the specialists we have brought the date forward."
Meanwhile, defender Zat Knight has urged his team-mates to get 'serious' about their predicament following a woeful start to the season.
The Trotters are currently bottom of the table with one win from six games and have taken just three points from a possible 18 on offer.
"The last few weeks have been very frustrating," he told the Bolton News. "Take away the Carling Cup performance and it has been very hard to motivate each other.
"We're at the bottom because we haven't done well enough in the last five games and something has to change.
"Everyone has to be a bit more competitive and take things a bit more seriously. Individually, we need to inherit more responsibility because when you look back at some of the goals we have conceded, it's been a case of slack defending or someone's runner has gone off them. That's the difference.
"We need to get back to being difficult to beat. When you don't win, you don't lose."