Derby County boss Paul Jewell admits Giles Barnes is set to miss the rest of the season.
Barnes sustained a knee injury in training last week, and while the exact nature of the problem has yet to be diagnosed, boss Paul Jewell has no intention of rushing him back.
"Claude's operation was very successful, but from the date of that to training again is four months, so he'll be fine for pre-season in June," added Jewell on the club's official website.
"Ty is making more progress because he has been running, and come pre-season they'll both hopefully be starting."
Dean Leacock, meanwhile, should return to training later this week after sustaining a hip injury in the 2-0 defeat at Wigan on February 23.