The Ulster coach has also been boosted by the return of Ireland Internationals Andrew Trimble and Stephen Ferris who are named on a vastly experienced replacements bench.
The only change up front sees Fitzpatrick replace John Afoa at tighthead prop, where he is joined in the front row by hooker Rob Herring and Callum Black. Captain Johann Muller and Lewis Stevenson continue their hard working partnership in the second row, while the loose forward trio of Sean Doyle, Robbie Diack and Nick Williams will be hoping to continue their impressive form from last week.
Niall' O'Connor will start ahead of Paddy Jackson at flyhalf, with Michael Heaney retaining the number 9 jersey. Darren Cave has been promoted from the bench to start at outside centre at the expense of Chris Farrell. Luke Marshall, Michael Allen, Craig Gilroy and Jared Payne complete the backline.
Ulster will be hoping to improve their away form, having suffered defeats in their last two games on the road in the RaboDirect PRO12, at Connacht and Munster. The Ulstermen have won three of their last four encounters against Welsh regions, but have lost on their last four visits to the Principality.
Ospreys' seven game winning streak in the PRO12 ended in Italy last Friday, with a surprise 6-12 reversal to Benetton Treviso. Ospreys have won their last three matches at Liberty Stadium and lost only once to an Irish province last season: 14-15 to Ulster at Ravenhill on 24th February.
The last four fixtures between the two sides have all been won by the home side on the day, whilst Ulster's only victory at Liberty Stadium since 2006 was 20-16 in September 2009.
Anscombe is delighted to welcome back Ferris and Trimble to his match day squad: "When you bring players of that calibre back into the mix it gives everyone a lift. The two boys haven't played much rugby in a while so you have to put that in perspective and not expect too much from them this early. Putting them on the bench is a good way of easing them back in.
Explaining the changes to his starting team, he commented: "With Paddy Jackson it was a precaution with his calf; he's not 100% but he's feeling much better than he was and he's progressing well. It wasn't worth the risk and we wanted to give Niall another chance to show what he can do.
"Darren Cave was on the bench last week, he's been training with the team now for a few weeks and I though he came on for the last quarter of an hour last week and added greatly to the team. He's an International so he brings that experience to a youthful backline. Declan is the same, he's been training well and we wanted to have a look at him from the start."
Anscombe continued: "There are a lot of areas to improve on but you would expect that and the main thing is that we're progressing. Over the next few weeks we'll keep integrating players back into the team and that will allow us to keep developing and growing our game. Its early days and we've just got to keep our feet on the ground and know where we're at."
Ulster XV & replacements to face Ospreys, RaboDirect PRO12, Saturday 8th September, Liberty Stadium (6.30pm):
(15-9): J Payne; C Gilroy, D Cave, L Marshall, M Allen; N O'Connor, M Heaney;
(1-8): C Black, R Herring, D Fitzpatrick, J Muller (c), L Stevenson, R Diack, S Doyle, N Williams;
Replacements (16-23): N Brady, T Court, J Afoa, N McComb, S Ferris, P Marshall, P Jackson, A Trimble.
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland