Saracens v Ospreys: Teams

Ospreys will be without Nikki Walker for Sunday's Heineken Cup quarter-final after the Scotland wing suffered a stress fracture of his right fibia.

He joins Wales scrum-half Mike Phillips, who is recovering from a serious knee injury, in missing the trip to Vicarage Road.

Phillips will not play again until next season, while Walker is set to be out for a month and will also miss the EDF Energy Cup final on Saturday week.

Former All Black Justin Marshall takes over from Phillips, with Johnny Vaughton replacing Walker. Ospreys head coach Lyn Jones still fields 12 members of Wales' Grand Slam squad.

Cracker

Ospreys beat Sarries 30-3 in the EDF Energy Cup semi-final two weeks ago.

Jones said: "Sunday's game is sure to be a cracker, with two good sides fully aware of what is at stake.

"It is always a strange situation when you face a side twice in such short succession, but it's fair to say that we won't be taking anything for granted, despite the manner of our victory at the Millennium Stadium two weeks ago.

"Back-to-back matches can be completely different affairs, as our own experiences against Ulster in this tournament in December show.

"We recorded a comfortable win at the Liberty Stadium, but it was a much tighter affair at Ravenhill the following week.

Message

"The message that we've been getting across to our players all week is that they must stay focused, keep their confidence in check to avoid any complacency and forget what has happened in the past."

Saracens boss Alan Gaffney has recalled centre Andy Farrell, prop Cobus Visagie and flanker Richard Hill, while wing Richard Haughton also features as a fourth change from the side that crushed Leeds Carnegie 66-7 last week.

Gaffney said: "We got the kind of performance we wanted against Leeds, and we have to take that into Sunday's game.

"We know the Ospreys will be a completely different opponent, but the fact is we have to go out on the front foot and attack them."

Saracens: 15 B Russell; 14 R Haughton, 13 K Sorrell, 12 A Farrell, 11 K Ratuvou; 10 G Jackson, 9 N de Kock (capt); 1 N Lloyd, 2 M Cairns, 3 C Visagie, 4 H Vyvyan, 5 K Chesney, 6 P Gustard, 7 R Hill, 8 B Skirving.
Replacements: 16 F Ongaro, 17 C Johnston, 18 T Ryder, 19 D Barrell, 20 M 21 Rauluni, 22 A Powell, 23 F Leonelli.

Ospreys: 15 L Byrne; 14 J Vaughton, 13 S Parker, 12 G Henson, 11 S Williams; 10 J Hook, 9 J Marshall; 1 D Jones, 2 H Bennett, 3 A Jones, 4 I Gough, 5 A-W Jones, 6 J Thomas, 7 M Holah, 8 R Jones (capt).
Replacements: 16 R Hibbard, 17 P James, 18 I Evans, 19 20 F Tiatia, 21 R Webb, 22 A Bishop, 23 A Brew.

Referee: Alan Lewis (Ireland).