Matt Williams has made 10 changes to the side that beat Queenslands Reds ahead of Ulster's meeting with Worcester at Ravenhill.

Ireland internationals Andrew Trimble and Ryan Caldwell return to the side, while hooker Rory Best drops out of the squad and is replaced by Nigel Brady for tomorrow's game.

Props Tom Court and Bryan Young swap sides, meaning the latter will start at tighthead and Italian Carlo Del Fava starts beside Caldwell in the secondrow.

Behind the scrum, Paddy Wallace and Timoci Nagusa are the only survivors from the Reds win.  The Ireland back will form partnership with scrumhalf Paul Marshall, while Nagusa on the right wing and Mark McCrea on the left.

Trimble is at outside centre with Paul Steinmetz at number 12.

Worcester will field new signing Chris Latham for the first time. The Australian, who is currently the Wallabies' second highest tryscorer, has recovered from injury and will bring a potent attacking threat to Mike Ruddock's side.

"We are delighted to be able to give Chris Latham a first start now he has made a full recovery. He is very keen to get started for the club and we look forward to seeing him in a Warriors shirt for the first time, it will be a special moment for the club," said Ruddock today.

Williams says the match will be another "step up" for his men.

"They are like us, coming to the end of our pre season and gearing up for the start of a big league campaign. It will be another step up, but at the same time, what has been good for us in that we are seeing young players coming through who have shown us they are ready for the next step," said the Australian.

"I have been really encouraged by the players over the last few months in particular for the two pre-season games, their commitment and attitude has been exceptional and the Worcester game will be a good test for some players who haven't featured against either Bath or the Reds.

"We play Scarlets next Friday at Ravenhill and start what we hope will be a successful league campaign, so obviously a win against Worcester would be a great boost for the players."

Ulster Team: B Cunningham; T Nagusa, A Trimble, P Steinmetz, M McCrea; P Wallace, P Marshall; T Court; N Brady, B Young, C Del Fava, R Caldwell, K Dawson(Capt),C Henry. Replacements (16-26) S Philpott, J Fitzpatrick, R Diack, W Faloon, C Willis, T Anderson, I Humphreys, I Whitten, C Cochrane, N O'Connor, R Dewey