The pacesetting Students - the only side in the top flight not to have lost a game so far - have been out of action since their 20-all Colours draw with Trinity on November 19.

John McClean has made just one change from the XV which earn a late share of the spoils through full-back Ross McCarron's try, with Leinster's David Blaney replacing Conor Geogeghan at hooker.

'Rock, who are coming off last Saturday's thrilling 33-17 defeat of Ballymena, have shifted free-scoring centre Andy O'Neill to the right wing, with Paul Graham possibly deputising in midfield, with Leinster's David Quinlan unavailable.

'Rock coach and former UCD favourite Steve McIvor has the luxury of an unchanged pack, as the visitors look for a repeat of last February's 16-9 success.

Belfast Harlequins got their semi-final bid back on track when edging a previously unbeaten Garryowen 13-6 last weekend. South African WP Strauss, who kicked eight points in the win and set up full-back Jonny Lowe for the only try, retains the fly-half place ahead of Ian Humphreys, for the visit of Shannon.

'Quins' Ulster rivals Ballymena - currently fourth from bottom - should chalk up their second win of the season, when entertaining Dublin University at Eaton Park.

New coach Steph Nel has included Ulster fly-half Paddy Wallace at 10, with provincial prop Bryan Young lining out at loosehead.

Elsewhere in the top flight, fifth-placed Buccaneers welcome Dungannon to Dubarry Park, with half-back duo Colm Glynn and David Connellan, who started for the first time this season in last Saturday's 23-21 win at Carlow, to renew their partnership.

Lansdowne welcome back young flanker Niall Ronan from Ireland Sevens duty for the visit of lowly County Carlow. The midlanders coach Ray Ward has left a vacancy at left wing for the visitors - who have not won an AIL fixture since March (34-19, away to UCD).

Cork Con will hope to avenge what was a testing 37-24 win for them last season, against plucky Galwegians at Temple Hill tomorrow, while in the battle of second and third, Garryowen visit Clontarf, aiming to repeat their 18-16 win of last season.

Dolphin should have six-try hero Tomas O'Leary back at scrum-half for their visit to first-placed De La Salle in Division Two.

In Division Three, Greystones lead the way after six games - one point clear of Sunday's Well and with a game-in-hand.

'Stones have a solid +122 points difference.

The Wicklow side - with the likes of Conor McNaughton and David McKechnie in particularly good form - should have enough to see in 2004 with victory over City of Derry.

Fixtures: Saturday December 18 (kick-off 2.30pm, unless stated)

Division One:

Ballymena v Dublin University, Eaton Park, 2.00pm Belfast Harlequins v Shannon, Deramore Park Buccaneers v Dungannon, Dubarry Park Clontarf v Garryowen, Castle Avenue Cork Constitution v Galwegians, Temple Hill Lansdowne v County Carlow, Lansdowne Road UCD v Blackrock, Belfield

Division Two:

Barnhall v Terenure College, Parsontown Bective Rangers v Old Crescent, Donnybrook DLSP v Dolphin, Kilternan,2.00pm Highfield v Old Belvedere Malone v Ballynahinch, Gibson Park Midleton v Young Munster, Towns Park St Mary's College v Waterpark, Templeville Road UCC v UL Bohemian, The Mardyke

Division Three:

Ards v Clonakilty, Hamilton Park Ballina v Corinthians, Heffernan Park Banbridge v Bruff, Rifle Park Connemara v Instonians, Monastery Field Greystones v City of Derry, Dr. Hickey Park Skerries v Old Wesley, Holmpatrick Suttonians v Wanderers. JJ MacDowell Park