Trimble had been given an extended break as part of the national team management programme since Ireland's tour to New Zealand in June, while Ferris has fully recovered from a calf injury he sustained in their Heineken Cup victory in May.

Elsewhere, Anscombe has made four changes to the team that beat the Glasgow Warriors 18-10 at Ravenhill, bringing in Mike McComish, Declan Fitzpatrick, Niall O'Connor and Darren Cave as they seek to win just their second match at the Liberty Stadium since 2006.

And even though Trimble and Ferris will start from the bench, Anscombe - taking charge of just his second game for Ulster - feels their mere presence will lift the rest of the squad.

"When you bring players of that calibre back into the mix it gives everyone a lift," he said.

"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

"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. I

"Its early days and we've just got to keep our feet on the ground and know where we're at."

The Ospreys' defence of their crown began in the worst possible fashion with a 12-6 reverse to Italian side Treviso.

Head coach Steve Tandy responds by selecting exciting Welsh half-back pairing of Rhys Webb and Matthew Morgan while the suspended Ian Evans is replaced by veteran Wales's second-row Ian Gough.

But Ospreys second row Alun Wyn Jones believes there is no need to panic maintaining the season is a marathon rather than a sprint.

"There are no big red buttons being pushed or anything like that," said Jones.

"We have to pick ourselves up and move forward. It's the first game of the season. We know where we are, what we need to do and where we are going.

"We look at each other and don't worry about what other people are thinking about us. We will look around the room and realise what we have to do and move on.

"The beauty is that it is the first game of the season and there will be plenty more opportunities to put things right and gain momentum over the season."

At Liberty Stadium, 6.30pm.

Referee: Neil Paterson (SRU, 42nd competition game)
Assistant Referees: Neil Hennessy, Phil Fear (both WRU)
Citing Commissioner: Russell Howell (WRU)
TMO: Tony Rowlands (WRU)
Live on S4C