Ulster are however boosted by the return of Ireland internationals Stephen Ferris and Rory Best, who were absent from the error-strewn defeat to Glasgow.

And while Springbok lock Muller admits his side are low on confidence at present, he believes the problem is all in Ulster's heads as they look to continue a formidable record of losing just once in their last 12 appearances at Ravenhill.

"Sometimes the harder you try, the worse it gets," said Muller.

"We are at a stage where we are so scared of making mistakes that that is exactly what is happening.

"It's all about confidence. I said to the guys that we have to get that balance right between trying too hard and not trying at all. That is the problem at this stage.

"We have been working at it very hard. We are more disappointed that anyone else.

"It all boils down to those small things, and confidence does make a difference. We have been training superbly and if we can only take that type of preparation into the game on Friday we can beat any side."

Ulster will be up against however as they face a Scarlets side currently riding the crest of a wave and unbeaten in eight matches in all competitions, having last lost on October 1 to Treviso.

Scarlets also prevailed 24-17 when these two sides met in October but head coach Nigel Davies, who gives starts to two Llanelli RFC players - lock Adam Powell and 19-year-old wing Iolo Evans - is taking nothing for granted.

"We know that Ulster will be at full strength and some may say that without our internationals it's more of a challenge - but all our players are keen to wear the shirt at the moment.

"There's a huge game against Munster on the horizon, so they'll want to take their opportunities in a bid to get selected for such a big fixture for the club.

"We have a few new Scarlets in our side on Friday night, but we're also strong on experience and ability and we go to Ulster on the back of a good run and with a lot of energy, enthusiasm and forward momentum.

"It is a very competitive environment at Parc y Scarlets the moment and that creates a positive drive and ambition throughout the squad."

At Ravenhill, 7.05pm
Referee : Alain Rolland (IRFU, 47th competition game)
Assistant Referees: Dudley Phillips, Eanna O'Dowd (both IRFU)
Citing Commissioner : Peter Ferguson (IRFU)
TMO: Marshall Kilgore (IRFU)

Live on BBCNI