GAVIN Henson will miss Wales' tour of South Africa next month after undergoing ankle surgery.

Ospreys centre Henson faces 12 weeks on the sidelines, meaning he has no chance of facing the Springboks in Bloemfontein and Pretoria.

The news will be a major blow to Wales coach Warren Gatland, who saw Henson play an instrumental role during this season's Grand Slam success.

Gatland has already lost Henson's Ospreys colleague, scrum-half Mike Phillips, because of a serious knee injury, while Llanelli Scarlets number nine Dwayne Peel is battling to overcome a shoulder problem.

The Ospreys said Henson had keyhole surgery on damaged ankle ligaments yesterday - an injury he suffered during the Heineken Cup quarter-final defeat against Saracens almost four weeks ago.

And the specialist decided it would be in Henson's best interests to stabilise the joint, therefore ensuring no recurrence of the problem.

But that procedure also means a 12-week absence, ruling Henson out until next season.

The Ospreys, meanwhile, continue their Magners League campaign against Edinburgh tomorrow night.

Head coach Lyn Jones said: "Preparations for Friday night's game have been hampered a little by a number of injuries in the camp, which is inevitable when you get to the end of a long campaign.

"When you look at the difficult season that our squad has had with so many big games, it comes as no surprise to see players becoming fatigued, especially when the matches continue to come thick and fast.''