Former All Black star Christian Cullen is facing a race against time to make the start of Munster's Heineken Cup bid.
The full-back was due to make his debut for the Irish province against Cardiff next Friday but has been ruled out after injuring his shoulder in his last game for Wellington.
Cullen was crocked during the recent NPC final in New Zealand against Auckland and now faces a second examination to assess the extent of the damage.
It is feared that Cullen, Munster's major signing of the summer, may be sidelined for up to two months though coach Alan Gaffney still hopes for good news.
"Christian has trained with us, but obviously avoided full physical contact," said Gaffney.
"It's doesn't appear to be a serious injury but we must ensure that he gets the best possible advice."
Losing a player of Cullen's stature and ability for half of the pool stage would be a major blow for Munster who are aiming to win the European crown for the first time having twice lost in the final.
"It remains to be seen how long this will take, but we are hopeful that it's not that bad," said Gaffney.
The 27-year-old Cullen was left out of New Zealand's World Cup squad after 58 appearances in which he scored 236 Test points, including a record 46 tries.
