Cardiff Blues will travel to Glasgow in the Magners League on Friday without star centre Casey Laulala, who has a hamstring injury.
The Blues, who hold the last play-off place, may be 12 points adrift of the leaders, but have a game in hand over all three teams ahead of them, as well as their nearest rivals for a top four spot, Ospreys.
Despite having won their last five games against Scottish opponents and winning their last two matches against Glasgow, they travel to Scotland missing a number of key players through international calls ups, injury and suspension.
Ben Blair is still out with a knee injury, Gethin Jenkins recovering from an operation on his toe, Michael Paterson out with a foot injury, Lloyd Williams out with an injured shoulder and Tom Shanklin recovering from knee surgery.
The Blues have been dealt a further blow with the news that Laulala is expected to be out of action for about three weeks with a hamstring strain suffered against Harlequins last weekend. Tom Davies also suffered a calf strain in that match and won't feature for four weeks, while Richie Rees is suspended until the end of March.
There is better news for the Blues with second row forward Deiniol Jones returning to action after treatment to a bulging disc in his back and is joined on the bench by Xavier Rush who has recovered from and injured neck.
Bradley Davies, Leigh Halfpenny, Jamie Roberts, Sam Warburton and John Yapp are all in the Wales squad, as in Chris Czekaj who was called into the squad on Monday.
Scott Andrews returns from the Welsh squad to start in the front row.
Meanwhile, Glasgow Warriors are hoping to kick-start a winning weekend for Scotland as both Glasgow and Edinburgh, plus the national team and a number of representative teams, all face Welsh opposition over the next two days.
Among eight changes from the 16-23 win against Newport Gwent Dragons in the Heineken Cup on 23 January, the Warriors welcome rookie fly-half Duncan Weir from injury.
"It's good news to have Duncan back after the shoulder injury he sustained playing for Scotland 'A'," said Head Caoch Sean Lineen continued.
"A lot is expected of Duncan in his first year, but he sets very high standards for himself so the players around him, like Colin Gregor at nine and Peter Murchie at 12, need to help him."
Weir will partner Colin Gregor at half-back to create a new partnership behind the scrum. Gregor has also been awarded the captaincy as Lineen sees the scrum-half's leadership and rugby skills continue to improve.
"Budgie's (Gregor) really improved. He is a very skilful ball player but he's added a little edge to his game," continued Lineen.
"He's taken on the role of leader and is leading by example which is what you want in a captain.
"It's potentially a very exciting pairing at nine and ten. You want to have threats right across your backline and both Colin and Duncan are threats in their own right."
The only other change in the back division sees Hefin O'Hare come onto the wing in place of Colin Shaw who drops to the bench.
In the pack, Glasgow field an entirely new front row as prop Ryan Grant is given the nod ahead of Jon Welsh whilst hooker Dougie Hall and tight-head Moray Low are on Scotland duty. Although, Hall has been withdrawn from the Scotland match-day 22 due to a shoulder problem.
Ed Kalman comes in for Low and Fergus Thomson replaces Hall.
New signing Tom Ryder will make his first appearance since signing with the Warriors and will once again fill the void he occupied whilst Al Kellock was out injured earlier in the season. This time, however, Kellock will be leading his country out of the Murrayfield tunnel for the first time.
In the back-row, Calum Forrester returns from a knee injury in place of Richie Vernon, also on Scotland duty, and Johnnie Beattie comes in for Ryan Wilson who drops to the bench.
Form: Glasgow Warriors have won their last two games, against London Wasps and Newport Gwent Dragons in the European Cup. The Warriors' only victory in their last four Magners League matches was 30-18 at home to Edinburgh on 27 December. Cardiff Blues have won their last two matches in the Magners League but have been victorious just once on the road in their last five encounters in all competitions. The Blues have won their last five games against Scottish opponents. The Blues have won their last two matches against Glasgow.
Glasgow Warriors: 15 Bernardo Stortoni, 14 Hefin O'Hare, 13 Federico Aramburu, 12 Peter Murchie, 11 DTH van der Merwe, 10 Duncan Weir, 9 Colin Gregor (c), 8 Johnnie Beattie, 7 Calum Forrester, 6 Robert Harley, 5 Tom Ryder, 4 Aly Muldowney, 3 Ed Kalman, 2 Fergus Thomson, 1 Ryan Grant.
Replacements: 16 Finlay Gillies, 17 Kevin Tkachuk, 18 Jon Welsh, 19 Chris Fusaro, 20 Ryan Wilson, 21 Henry Pyrgos, 22 Peter Horne, 23 Colin Shaw.
Cardiff Blues: 15 Dan Fish, 14 Richard Mustoe, 13 Gavin Evans, 12 Dafydd Hewitt, 11 Tom James, 10 Ceri Sweeney, 9 Tom Slater, 8 Ma'ama Molitika, 7 Martyn Williams, 6 Andries Pretorius, 5 Pau Tito, (c) 4 Bryn Griffiths, 3 Scott Andrews, 2 T Rhys, Thomas, 1 Tafa'ao Filse.
Replacements: 16 Gareth Williams, 17 Sam Hobbs, 18 Nathan Trevett, 19 Deiniol Jones, 20 Xavier Rush, 21 Rhys Downes, 22 Lewis William,.s 23 James Loxton
Date: Friday 11 February
Venue: Firhill Stadium, Glasgow
Kick-off: 19.35 GMT
Referee: Dudley Phillips (IRFU)