Have you considered selenium and zinc supplements?
From www.rovers.co.uk
Ryan first sustained the injury in a league game with Everton at
Ewood Park last December and despite playing a key role throughout
the rest of the campaign, was unable to fully shake it off.
The Kiwi defender then broke his leg away at Charlton in late April,
but returned for pre-season fully rested and with a positive scan
result to boot. But as the new season approached, Ryan admits that
he perhaps didn't really give it sufficient time to heal and before
long, his initially-torn hamstring attachment had become completely
ripped from the bone.
full story on the official site. Sorry guys, unless Lee says it's fine to cut and paste full articles, we can't do it.