Both Morgan Stoddart (with ball) and Mark Jones will miss the clash against Stade Francais at Parc y Scarlets.
The Scarlets are bracing themselves for the sternest of French tests when Parisian aristocrats Stade Francais arrive for a Heineken Cup clash at Parc y Scarlets on Sunday.
Harlequins currently sit on top of Pool 4 but the French outfit know that only a bonus point victory will keep them in the hunt - but only if other results in the group go their way as well over the next couple of weeks.
Scarlets Head Coach Nigel Davies has an injury crisis on his hands and as a result has had to name four scrum halves in his squad.
Sevens specialist Lee Williams fills in on the wing with both Dafydd James and Mark Jones out, while Gavin Cattle and Sililo Martens are both on the bench as backs resources are stretched to the limit.
Scarlets Head Coach Nigel Davies is fully aware of the difficult challenge ahead for his side.
"Stade are quality from one to 15 - and if you start to worry too much about one or two of their players you're likely to be caught out elsewhere.
"They have tremendous individuals; they don't play the most expansive rugby all the time but when they do decide to play they're pretty devastating.
"I think, realistically, that if they want to qualify they've got to come here and get a bonus point so maybe they'll look to be a bit more expansive than normal this weekend."
Scarlets fly-half Stephen Jones added: "Stade have got great players in key positions and play a little differently - quite deep as a back line, trying to hit you hard first and second phase playing quite deep. They'll kick quite a lot on Sunday, trying to put us under pressure but hopefully we won't fall into that trap because we're gathering momentum quite nicely now.
"A lot of our youngsters have been getting five or six games on the bounce so that's great for them and for the whole squad because when everyone's fit again it's going to be a very competitive place."
Injuries to the Scarlets' Rhys Priestland (knee) and Morgan Stoddart (collarbone) mean that Ceiron Thomas comes in at full-back and Lee Williams on the wing.
Davies said: "The injury situation behind the scrum is pretty grim at the moment, particularly when you take into account the limitations that European registration can put upon you.
"For this weekend we've got nine fit backs - and four of those are scrum-halfs! Apart from Martin Roberts, they include Lee Williams who's played in a number of positions and on the sevens circuit - he can play 10 or on the wing. Another, Gavin Cattle ended up on the wing for us last Friday night at Connacht.
"Two wings we've used recently - Gareth Morris and Yannick N'gog - aren't registered for Europe. More important than that, however, is the way that this group is developing. If I reflect back on the early part of the season, we started the campaign well but when it came into the high-pressure, high-intensity matches of Europe we fell short and probably some of the scars from the previous season were still there in terms of the mentality of the group.
"What I believe we were able to do around the Christmas period - and since then - is really put a lot into this team from the mentality point of view. As a result we've come back to win games that we hadn't been in for substantial periods. That's probably something we wouldn't have done in the past so that's been a really pleasing thing for me.
Jones added: "We're a developing side and of late we've improved quite a bit so the game for us now is to keep moving forward and to keep raising the bar. One of the best teams in Europe gives us an opportunity to do that. Stade have massive quality throughout their squad and whoever starts will be a quality player."
Scarlets: 15 Ceiron Thomas, 14 Darren Daniel, 13 Regan King, 12 Jon Davies, 11 Lee Williams, 10 Stephen Jones, 9 Martin Roberts; 1 Phil John, 2 Matthew Rees, 3 Deacon Manu, 4 Vernon Cooper, 5 Dominic Day, 6 Simon Easterby (c), 7 Johnathan Edwards, 8 David Lyons.
Replacements - 16 Ken Owens, 17 Iestyn Thomas, 18 Simon Maling, 19 Dafydd Jones, 20 Josh Turnbull, 21 Gavin Cattle, 22 Sililo Martens.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.