The 26-year-old showed why he was set to play an important part in Ireland’s attempts to regain the Six Nations title by helping Ulster triumph 43-6 in Viadana to progress to the quarter-final stage for the first time in 12 years.

But for Trimble history came as a price and a post-game X-ray confirmed he had broken a metacarpal in his hand which will almost certainly rule him out of Ireland’s opening two games with Italy and France.

“Trimble picked up the injury during the Heineken Cup match at the weekend playing for Ulster against Aironi and, following an X-ray, it was found that he had broken a metacarpal in his hand," said a team spokesman.

"This will definitely keep him out of the Italy game and he will have a specialist review this week to determine how long he will be unable to play for."

Four weeks is likely to be the minimum Trimble will spend on the sidelines while former Ulster winger Tommy Bowe is also battling to be fit after injuring his knee, a fate that has also befallen back row Stephen Ferris.

"It's hopefully okay," said Bowe. "Fingers crossed I'll be fit. It doesn't feel too sore at the minute. It's not too bad."

Rory Best should be fit despite sitting out Ulster’s final pool game with a rib injury sustained in the 9-6 win over Biarritz.