Injured Jones has been badly missed by the Ospreys this season

"We have underperformed this season, but that is largely due to injuries to key players," said Ospreys joint- managing director Mike Cuddy.

"Ryan is one of those. He's had a bad time but will return to cement his spot as one of the world's best back-rows."

Jones is out until next season after surgery to reconstruct his shoulder.

The 6ft 5in powerhouse picked up the original injury on the Lions tour, where he played a starring role after being called up as an injury replacement.

He then aggravated the problem in his first appearance of the season, against Bath for the Ospreys in October.

The return of players such as Ryan will lay the foundations to what I am sure will be a successful 2006-7 season Mike Cuddy

His operation in November was a success, but he still faces a long period of rehabilitation.

"The return of players such as Ryan will lay the foundations to what I am sure will be a successful 2006-7 season," said Cuddy.

"We are confident in the direction we are taking and key personnel are keen to commit themselves to the Ospreys.

"Ryan approached us after the Lions tour at a time when other sides were expressing an interest in signing him.

"Since then it has proven to be a difficult time for Ryan and it is a measure of our commitment to him that we are extending his contract at this time.

"Ryan is the type of player that is always keen to work on his weaknesses."