Pro12 Players' Player of the Year Charles Piutau will spend the off-season recovering from ankle surgery after Ulster confirmed the versatile Kiwi back is out for two months.
Piutau had been named in the Barbarians squad to face England at Twickenham on Sunday week, but his club confirmed on Wednesday that he's facing eight weeks' recuperation. He was also dues to play for Ulster against the Baa-Baas four days later .
He played in Ulster's final game of the season, a 17-13 defeat of Leinster at Kingspan Stadium.
Les Kiss's men required of a bonus-point win over their provincial rivals while closing the Ospreys' 73-point scoring difference advantage to sneak into the Pro12 play-offs after a disappointing campaign.
They fell short of that lofty target, but were at least able to give the departing Ruan Pienaar and Roger Wilson a worthy send-off.
Wiehahn Herbst (knee) and Stuart Olding (ankle) had successful surgery on their respective injuries and are both expected to be fit for start of next season.