Celtic League/Ulster v Leinster At Ravenhill. ON TV: (Setanta Sports, 7.30):Leinster coach Michael Cheika appears to be an advocate of a cloak-and-dagger selection policy. In announcing his squad earlier in the week for tonight's Magners Celtic League clash, he included Felipe Contepomi and omitted Brian Blaney. Yesterday the Argentinian outhalf was nowhere to be found in the match squad while Blaney was named as the replacement hooker.

It's unlikely Ulster will be fazed by the selectorial sleight of hand and one presumes there will be more genuine substance to Leinster's on-pitch challenge. The former Springbok international Ollie Le Roux will complete his first week in Ireland by lining out at loosehead prop in a front row that includes Bernard Jackman and Stephen Knoop.

Jamie Heaslip, Leo Cullen and Chris Whitaker return after injury, Shane Jennings is preferred to Keith Gleeson in the back row, and Ireland and Leinster captain Brian O'Driscoll, Gordon D'Arcy and Girvan Dempsey return to competitive fare for the first time since the World Cup.

Rob Kearney has prevailed in the battle of the tyros and claims the left-wing berth ahead of the province's leading try scorer this season, Luke Fitzgerald, who must content himself with a place on the bench.

Leinster's record at Ravenhill is excellent, their last defeat in Belfast coming in May, 2004, but as with any domestic spat, this will be keenly contested.

Malcolm O'Kelly is well versed in the demands of the fixture.

"All the international players are keen to get back involved with a winning set-up," he said. "There are some new faces who look to have settled in well, and Ollie Le Roux brings with him a wealth of experience. He's a good guy and he's not short of a few words, which is no bad thing, so I'm sure he'll be a good addition to the squad.

"Obviously the likes of Leo (Cullen) and Jenno (Shane Jennings) would have been familiar with the set-up from their previous spells and they can also contribute in terms of the experience they gained with Leicester.

"The challenge for us as players is to tighten up our play over the next few weeks. We've done quite well on the road so far - winning in Cardiff and losing a game we probably should have won in Glasgow - so it's important that we up our game against a good Ulster side who will be strong opponents in their own backyard.

"They're a strong and a proud team and we're expecting a tough game, irrespective of league positions. They've added some good players to their squad, like Rob Dewey and Carlo Del Fava, while they have others coming back from injury."

Ulster coach Mark McCall gives a debut to the Scottish international Dewey, a player who has caused Leinster problems in the past with his strong, direct physicality. He will partner Andrew Trimble in what promises to be an interesting midfield battle.

McCall enthused: "They are both international players; individually they are both very strong and physical centres so it will be great to see them play alongside each other and see what they can do."

David Humphreys demonstrated he had recovered from an ankle injury by playing in the A clash between the provinces last Friday but must content himself with a place on the bench as Paddy Wallace is chosen to start at outhalf. It is a welcome fillip for Wallace given what he's endured recently.

Rory Best starts at hooker, with Justin Fitzpatrick named at loosehead and Bryan Young at tighthead, while the promising start made by the Italian international Del Fava to his time in Belfast is reflected in his selection alongside the returning Ryan Caldwell in the second row.

Stephen Ferris is preferred to Roger Wilson at number eight, while Kieron Dawson will start at openside flanker. Ulster find themselves at the foot of the table and desperately needing to kick-start their season as the upcoming Heineken European Cup begins to cast a longer shadow.

Rediscovering the set-piece solidity, the precision of execution and good decision-making would be facilitated by a mental edge that has been lacking in recent games. The home side need to put pep in their step.

Leinster snatched defeat from victory in Glasgow. Cheika will be hoping the returning Ireland internationals will boast a hunger and ruthlessness that will be essential qualities over the coming four weeks.

Ulster may be at home but Leinster appear in marginally better fettle.

ULSTER:B Cunningham; T Bowe, A Trimble, R Dewey, M McCrea; P Wallace, I Boss; J Fitzpatrick, R Best (capt), B Young; C del Fava, R Caldwell; N Best, K Dawson, S Ferris. Replacements: N Brady, D Fitzpatrick, J Harrison, R Wilson, P Marshall, D Humphreys, M Bartholomeusz.

LEINSTER:G Dempsey; S Horgan, B O'Driscoll (capt), G D'Arcy, R Kearney; J Sexton, C Whitaker; O Le Roux, B Jackman, S Knoop; L Cullen, M O'Kelly; S Keogh, S Jennings, J Heaslip. Replacements: B Blaney, S Wright, D Toner, K Gleeson, C Willis, L Fitzgerald.

Referee:G Clancy (IRFU).

Last meeting -At Lansdowne Road: Leinster 20 Ulster 12.

Leading points scorers:Ulster - Niall O'Connor 23. Leinster - Jonathan Sexton 48.

Leading try scorers:Ulster - Mark Bartholomeusz, Tommy Bowe, Simon Danielli, Tom Court, one each. Leinster - Luke Fitzgerald, three.

Verdict:Leinster to win.

Promising young Leinster centre Fergus McFadden could be out for six months after suffering a cruciate knee injury while playing in the A interprovincial between Leinster and Ulster.

How They Stand

P W D L F A B Pts

Cardiff6 5 0 1 157 107 3 23

Llanelli6 4 0 2 171 107 4 20

Ospreys6 2 1 3 106 87 3 13

Dragons6 3 0 3 116 135 0 12

Leinster4 2 0 2 93 100 2 10

Munster4 2 0 2 72 67 1 9

Glasgow4 2 0 2 76 101 0 8

Edinburgh4 1 1 2 58 65 1 7

Connacht4 1 0 3 64 87 1 5

Ulster4 1 0 3 46 103 0 4