Updated at 20.00 

IRELAND HAVE BEEN dealt a major blow ahead of the Under 20 World Championship in Italy, after star out-half Ross Byrne has been ruled out with a back injury.

Byrne had been one of Nigel Carolan’s stars in this season’s Under 20 Six Nations Championship, starting all five of Ireland’s games, and he was also a vital member of the Under 20 team that finished fourth in last year’s World Championship.

The Leinster fly-half has scored 129 points in 15 appearances for the Under 20s in the past two years.

The IRFU confirmed this afternoon that a back injury would rule the 20-year-old out of the tournament, and they have called Munster’s Tomás Quinlan up as cover.

Quinlan is uncapped at this level for Ireland, but has played a number of games for Munster’s A team, as well playing regularly for Cork Constitution in the Ulster Bank League, earning a nomination for Rising Star of the Year at the 2015 end of season awards.

Quinlan’s inclusion brings to three the number of Munster players in the squad, along with winger Stephen Fitzgerald and hooker Sean McNulty

Ireland share pool C with Argentina, Scotland and New Zealand and open their tournament against Argentina on Tuesday, 2nd June in Stadio Sergio Lanfranchi, Parma.

Under 20 star Ringrose digs in to make sure feet don’t leave the ground