SHANE HORGAN returns to the Leinster squad for Saturday's Magners League clash with the Dragons at the RDS but coach Michael Cheika confirmed Leo Cullen had elected to undergo shoulder surgery that will keep him sidelined until the end of the summer.

It's an unfortunate and untimely blow for the Leinster secondrow, who has been in excellent form for his province this season, both as player and leader.

He would have been a strong contender for a place on Ireland's summer tour to New Zealand and Australia but instead must now focus on his rehabilitation.

Cheika acknowledged: "Leo Cullen had a shoulder operation last week and he will be out for the next few months.

"It's a massive blow for him because he has been so consistent for us this season and had put himself right up there for (Ireland) selection in what is one of the most competitive areas."

Gordon D'Arcy is the only other front-line absentee.

Cheika is keen to simplify Leinster's remit on Saturday, focusing on winning a match that would guarantee them the Magners League title.

There are mathematical permutations that could ensure the trophy even in defeat - they travel to face the Dragons at Rodney Parade next week - but they don't interest the Australian.

He pointed out: "I went down to see the Dragons against the Ospreys last weekend and we understand the importance of this week's game. We're concentrating on our opponents and we will be doing our best to get the right result.

"We've been voted the best-supported team in the Magners League again this year and we'd love to beat the Dragons for them (supporters) on Saturday. But first things first; our focus is on the game and not the occasion.

"I feel that we're in far better shape this year. We have definitely managed the players differently, in that we might have taken them out of training at particular times. Our mental and physical conditioning, player preparation - things like that - have improved, and though we've had some disappointment in recent years, if I didn't learn from those experiences then they would have been wasted.

"We know that our consistent performances all year have gotten us this far."

Saturday will be an emotional occasion, not just because there is silverware at stake but also because a couple of key players will be lining out in a Leinster jersey in front of their home supporters for the last time.

Ollie le Roux returns to South Africa, and Keith Gleeson has decided to retire at the end of the campaign, a couple of months short of his 32nd birthday.

Cheika paid tribute to Gleeson, a player who has served his province and Ireland with distinction.

"We want him to finish on the right note as well, because it's important that when players leave, they do so with good memories. He has played some awesome games for us and I actually think he has gotten better this season in terms of his defence, his ball play and his distribution."

The Leinster coach confirmed he had not been approached by the IRFU in the context of any interim coaching assignments with the national team and was unequivocal in his views on who should get the position vacated by Eddie O'Sullivan.

"I think that he (Declan Kidney) should get it. He's Irish, he has gotten his team to the pinnacle of the game in Europe and they have been consistent performers in the Magners League. He's breeding Irish players and I've got a good rapport with Declan.

"If/when he does get it I'm sure that he will do a good job. I will do anything I can to get my players playing for their country."

First, though, there is a small matter of collecting some silverware at the weekend.

LEINSTER (squad v Dragons):C Healy, O le Roux, B Blaney, B Jackman, S Knoop, S Wright, T Hogan, C Jowitt, M O'Kelly, D Toner, S Keogh, K Gleeson, S Jennings, J Heaslip, C Keane, C Whitaker, J Sexton, C Warner, R Kearney, M Berne, F Contepomi, B O'Driscoll, G Brown, L Fitzgerald, S Horgan, G Dempsey, F Jones.

RUGBY FIXTURES

TODAY

Magners League: Ulster v Munster, Ravenhill, 7.30.

FRIDAY

Magners League: Connacht v Cardiff Blues, Sportsground, 6.30; Ospreys v Edinburgh, Liberty Stadium, 7.10.

SATURDAY

Magners League: Llanelli v Munster, Stradey Park, 2.45; Ulster v Glasgow, Ravenhill, 3.0; Leinster v Dragons, RDS, 6.0.

AIB League Division One semi-finals: Cork Constitution v Clontarf, Temple Hill, 2.30; Shannon v Garryowen, Coonagh, 3.0.