CARDIFF BLUES (4th) v ULSTER (2nd), Arms Park, 7.10pm (live Setanta Sports Ireland/BBC Wales)
Team News: Ulster coach Mark McCall has made one change in personnel and one positional switch to the side that beat Border Reivers 33-9 last week, for Friday's trip to Cardiff.
Former Ireland out-half David Humphreys is suffering from an adductor muscle injury in training this week, so Paul Steinmetz returns in midfield with Paddy Wallace taking over from Humphreys at number 10.
Kevin Maggs has been included on the replacements bench, along with flanker Neil McMillan, who is returning to the matchday squad for the first since fracturing his thumb in January.
Ulster are currently second in the league table, just five points behind Leinster. Cardiff, who have two games in hand on McCall's side, are only six points behind Ulster.
Blues boss David Young has made two changes to the side that scored a record 48-0 win over Edinburgh last week. Jamie Robinson starts at centre with Taufaâ00ao Filise coming in at prop. Tom Shanklin and Gary Powell both drop to the bench.
Cardiff: Ben Blair; Rhys Williams, Jamie Robinson, Marc Stcherbina, Chris Czekaj; Nick Macleod, Mike Phillips; Gethin Jenkins, Rhys Thomas, Taufa'ao Filise, Bradley Davies, Robert Sidoli, Andy Powell, Martyn Williams, Xavier Rush (capt).
Replacements: Gary Powell, Gareth Williams, Deiniol Jones, Mark Lewis, Ed Fairhurst, Nicky Robinson, Tom Shanklin.
Ulster: Bryn Cunningham; Tommy Bowe, Andrew Trimble, Paul Steinmetz, Andrew Maxwell; Paddy Wallace, Isaac Boss; Bryan Young, Rory Best, Simon Best (capt), Justin Harrison, Ryan Caldwell, Stephen Ferris, Neil Best, Roger Wilson.
Replacements: Paul Shields, Justin Fitzpatrick, Tim Barker, Neil McMillan, Kieran Campbell, Kevin Maggs, Paul McKenzie.
Referee: Malcolm Changleng (Scotland)
Touch Judges: tbc
Team League Statistics: Cardiff: Top Points Scorer - Ben Blair 141 (5 tries, 19 conversions and 26 penalty goals); Top Try Scorer - Ben Blair 5
Ulster: Top Points Scorer - David Humphreys 148 (1 try, 25 conversions and 31 penalty goals); Top Try Scorers - Bryn Cunningham, Paul Steinmetz, Andrew Trimble 5 each
Previous League Meetings:
October 31, 2003 - Ulster 32 Cardiff Blues 7, Ravenhill
April 3, 2004 - Cardiff Blues 19 Ulster 15, Arms Park
November 19, 2004 - Ulster 30 Cardiff Blues 14, Ravenhill
April 8, 2005 - Cardiff Blues 22 Ulster 8, Arms Park
September 9, 2005 - Cardiff Blues 22 Ulster 25, Arms Park
May 5, 2006 - Ulster 26 Cardiff Blues 17, Ravenhill
October 14, 2006 - Ulster 32 Cardiff Blues 12, Ravenhill
- A win for either team would push their claims towards gaining the Magners League title, whilst for the losers it will probably mean that they drop out of the race
- Cardiff Blues have won their last dozen Magners League matches at the Arms Park, and have not lost at home to an Irish team in the league since Munster were the visitors in November 2005
- Ulster won last time out, beating Border Reivers 33-9 in Galashiels last Friday, but have lost on their last three visits to Wales in all competitions
- Ulster have won the last three encounters between the two sides including a 32-12 victory at Ravenhill in October, and have won two of the seven games they have played at the Arms Park in all competitions