Scrum-half Mike Phillips recently underwent surgery to repair damage to his anterior cruciate and medial collateral ligaments and will be out of action for approximately six months.

Wing Nikki Walker is suffering from a stress fracture of the fibia in the right leg. He is expected to be out of action for a further three to four weeks.

Hooker Barry Williams is undergoing a four-month rehabilitation programme following keyhole surgery on his hip in January and will not play again this season.

No 8 Filo Tiatia starts, having been on the bench against Saracens last Sunday.

Ospreys head coach Lyn Jones commented: "Saturday is another big day, another landmark occasion in the short history of the Ospreys and everybody in the camp is looking forward to going back to Twickenham to face Leicester Tigers in a repeat of last years classic encounter.

"Conceding 28 points in one half, is a freak event for any professional side and being a little wiser to the demands Leicester will place upon us, memories of last year will help drive us on to the goal of becoming the first Welsh side to win the EDF Energy Cup.

"Leicester are a very wise side who have been there and done it many times over the last 11 years. They may not have made it into the latter stages of the Heineken Cup this season but we still regard them as one of the big four in Europe.

"It's going to be a real test of our physical and mental stamina, following on from the boys 6 Nations success and then the disappointment of last weekend.

"Its disappointing news that we have to go into the game without Gavin Henson, who is still suffering from the ankle injury he picked up at Saracens, and although he just failed to make it for this weekend we are confident that he will be fit for selection next week.

"As is always the case, his absence provides someone else with an opportunity and in Andrew Bishop we have a talented youngster who has a considerable amount of experience for a 22 year-old and as part of the matchday squad who lost out to Leicester last season, he is looking forward to the opportunity to put the record straight.

"It's another big occasion for the supporters who will be there in their thousands. They provided tremendous backing last weekend, as they always do,and I'm sure it'll be no different again on Saturday.

"The noise they made at Twickenham last year really took a lot of people by surprise, here's to more of the same this time around and hopefully, we'll be able to give them something to celebrate come 4.15."

Ospreys team, v Leicester Tigers, EDF Energy Cup on Saturday at Twickenham:

15 Lee Byrne
14 Johnny Vaughton
13 Sonny Parker
12 Andrew Bishop
11 Shane Williams
10 James Hook
9 Justin Marshall

1 Paul James
2 Richard Hibbard
3 Adam Jones
4 Alun-wyn Jones
5 Ian Evans
6 Ryan Jones (capt)
7 Marty Holah
8 Filo Tiatia

Replacements:

16 Huw Bennett
17 Duncan Jones
18 Ian Gough
19 Jonathan Thomas
20 Gareth Owen
21 Jonathan Spratt
22 Aled Brew