There remained question marks over four key players yesterday afternoon when Ulster head coach, Matt Williams announced a 25-man squad ahead of what is a vitally important European Cup clash against the Llanelli-based club.

However, Rory Best (hooker), Stephen Ferris (backrow) and backs duo Paddy Wallace and Andrew Trimble, were included in the panel.

Ruled out already is Fijian winger Timoci Nagusa, who marked his try scoring debut for Ulster in the Heineken Cup during the defeat at Harlequins in London in October.

He pulled up with a hamstring strain during the 53-13 home win over Connacht in the Magners League and although he was having a second scan yesterday as part of the ongoing assessment, he was not included in the backs for selection.

Williams said he had high hopes Best, Ferris and Trimble would get the all clear, but he would give them as long as possible.

Trimble had a niggle during training last week before the Connacht game having just returned from Irish international duty and was not risked.

Williams said: "Rory, Stephen and Andrew all trained today and we are just waiting to see if there is any adverse reaction.

"Certainly the injury situation is a lot more positive than I thought it could have been on Sunday or Monday.

"But we will still not rush anyone back if they are not right."

Wallace was stretchered off during the match against Connacht following a clash of heads with lock Ryan Caldwell after just 25 seconds of the game.

Williams said: "At no time did Paddy lose consciousness following the collision, so that is a positive. However, he did have 'pins and needles' at the time and the medical team were rightly concerned and that was why we used the neck brace

"We are still waiting to sign off on him, but it looks good. He trained today with no ill effects and it is again a case of waiting and seeing how he reacts."

The head coach added: "At the end of the day my ethos is 'it is only a game of rugby' so we will not be pushing anybody to get back, unless they are ready.

"The medical team are looking after him, they are continuing to monitor him.