New Zealand back-rower Marty Holah is the latest big-name player to announce he is leaving the Ospreys.
The 35-year-old is returning home play for former club Waikato in the 2011 ITM Cup season later this year.
Holah has made 90 league appearances for the Ospreys during his four seasons at the Liberty Stadium.
"I feel it's time to move back home to be closer to my family and friends and to enjoy playing for my home province again," Holah told the Waikato website.
"I feel it's the right time to move while I still have something to offer the province that has given me so many opportunities."
The Ospreys could be hit by a further exit with Japanese side Yamaha Jubilo claiming on their website that ex-All Black flanker Jerry Collins is joining them, but the Welsh region have yet to confirm this.
The departure of Holah and possibly Collins adds to a list of key figures to say they are leaving the Ospreys.
Gavin Henson left earlier this season for Toulon via Saracens, while fly-half Jame Hook (Perpignan), full-back Lee Byrne (Clermont Auvergne) and prop Craig Mitchell (Exeter) have announced they are moving on at the end of the season.
And last week, the Ospreys also said that scrum-half Mike Phillips will be allowed to leave as soon as he finds a new club.
But the Ospreys have signed back-rowers Joe Bearman from the Dragons and Samoan George Stowers from London Irish while captain Alun Wyn Jones and Shane Williams have signed new deals.