Connolly is scheduled to have surgery on Monday in Colorado. The procedure will be performed by hip specialist Dr. Marc Philipon, who recently operated on Mike Sillinger and Rick DiPietro of the New York Islanders.
"It's extremely frustrating," said Connolly, who was bothered by the injury for much of the past three months and hoped to complete the season before having surgery. "It has to get done. It's gotten to the point where I can no longer go out and perform.
"It was bothering me quite a bit. The pain would get a lot worse playing."
Connolly missed 13 games from Jan. 10-Feb. 8, before returning to the lineup. The play-making center then played in 14 of the next 16 games, before aggravating the injury when he crashed heavily into the boards during Buffalo's loss to the New York Rangers on March 10. He hasn't played since.
"It was a combination of the time it took to recover, his inability to practice in between [games], and a rising level of pain," said Buffalo general manager Darcy Regier during the Sabres' 4-1 loss against Toronto. "We think he'll be fine for the start of next season."
With 40 points (seven goals, 33 assists) in 48 games, Connolly ranks sixth on the Sabres in scoring.
"He gave it his best shot," coach Lindy Ruff said. "He was playing with a lot of pain. The first two or three games were probably his best. After that, the pain didn't decrease."
The injury is the latest setback for Connolly, who missed all but two regular-season games last season because of a neck injury and post-concussion symptoms. He also missed the entire 2003-04 season because of a concussion.
"I'm not happy with the situation," Connolly said. "There's nothing you can do about it. It's not an injury that's avoidable."
Connolly has one year left on a three-year, $8.7 million contract, and is scheduled to make $3.5 million next season.
"We could certainly use him," Regier said. "It's what best for him and the organization."