Connacht’s worst fears were confirmed when a scan revealed significant knee damage which the 22-year old suffered in the 51-34 victory over Zebre on Saturday.

Masterson was taken to hospital in Parma having been stretchered from the field but he was able to return home with the squad on Sunday.

However, coach Pat Lam confirmed today that Masterson, who can play right across the three back row positions, will not feature again this season.

“He had an x-ray in Parma and further scans yesterday, so just awaiting results for that scan to determine the extent of that injury. But he is definitely ruled out for the rest of the season.”

Masterson has played in 13 of Connacht’s 15 league games this season, starting ten of them, and Lam said the Portlaoise native, who featured for Emerging Ireland in the Tbilisi Cup last summer, will be a big loss.

Thanks so much to all who sent messages after yesterday's game. In particular staff and players of @ZebreRugby who helped me with my injury.

— Eoghan Masterson (@EoghanMasterson) February 21, 2016

“He has had a very good season, he had been fighting in the back row. I think the biggest thing is just competition. We had guys in and out, injury and no one play eight, six and seven.

“But every time you lose an injury the main thing is you lose competition and that’s what is driving everybody. But the next guy steps up,” said Lam.

Connacht, who have already equaled their best league campaign ever last season when they chalked up ten wins and 50 points, are in pole position to nail down a first ever semi-final spot.

But Lam said they will be tested this weekend when they host an Ospreys who are coming to the Sportsground on the back of good wins away to Munster and home to Edinburgh.

Back rowers Jake Heenan (hip pointer) and Eoin Mckeon (ankle), along with centre Craig Ronaldson (knee) are being monitored this week after picking up injuries in the win over Zebre.