Joe Schmidt admitted it was "incredibly tough" to leave Devin Toner off Ireland's 31-man World Cup squad, stressing that Jean Kleyn's status as the only 'specialist tight-head second row' available was key to his inclusion. 

The Ireland head coach announced his squad this afternoon with the omission of Toner emerging as the major surprise.  

The 33-year-old Leinster lock was more or less an ever present for Ireland between 2014 and 2018, featuring in every game in Ireland's three Six Nations winning campaigns through that period. 

He also started in both victories over New Zealand during this World Cup cycle and was widely feted as a world class lineout operator. 

His 2019 season has been heavily interrupted after picking up a knee injury against England in Dublin in February and he only returned to competitive international duty during last month's warm-ups. 

"I've coached Dev for ten years. And he's not just a lineout champion for us, he's such a good player and an absolutely quality person," Schmidt told RTÉ Sport's Michael Corcoran today. 

"That was an incredibly tough conversation yesterday."

The South African-born Kleyn, who joined Munster in 2016, officially qualified to play for Ireland under eligibility rules at the beginning of last month. 

Schmidt has pinpointed his role in the scrum, as a 'tight-head second row', as the reason he's been given the nod ahead of Toner. 

His Munster team-mate Tadhg Beirne also made the grade, with the Ireland head coach highlighting his versatility and prowess at the breakdown. 

"Jean Kleyn? We probably don't have a specialist tight-head second row. At the start, I talked about the balance that we're looking for across that squad of 31. Jean Kleyn fitted that.

"Tadhg Beirne gives you the versatility of both a second row and he can play in the back row. He's teamed up really well with Jean Kleyn for Munster this year. And he also gives you the threat over the ball like a 6 or a 7 would.

"You've got James Ryan who made an immediate impression coming into the side and Iain Henderson who's promised so much and performed incredibly well for us at times. We're going to very much need him to put his best foot forward. 

"So, it was a very tight decision around Dev."