The British Lions and Wales Hooker has been out of action since an operation on his toe in early January and missed the entire Six Nations Championship, but has been passed fit for the Scarlets' big game.
"It's good to have him back," said Llanelli director of rugby Gareth Jenkins. "The Hooker position was a concern for us with Marcus Thomas out with a shoulder injury and, whilst young Aled Gravelle has done well for us in the last few weeks, you can't under-estimate the influence of someone with Robin's pedigree."
Llanelli have played 13 French sides at Stradey Park in the history of the club and lost to none, but Jenkins admits this game could be the biggest of them all.
"There is no doubt this is a massive game for this club," he said.
"The Heineken Cup is a special tournament, it's becoming a big part of Llanelli rugby club and we are proud to be representing Wales in Europe.
"Perhaps we go in as favourites, but that's only because we have home advantage.
"We have done our homework on Perpignan and they are obviously a very capable side with good performances against Agen and Gloucester already under their belts this season.
"But, hopefully, we will be able to give the capacity crowd at Stradey Park something to shout about."
Full-back Barry Davies is the only uncapped player in the starting side that is lead by centre Leigh Davies. Wing Garan Evans is selected ahead of recovering Wales wing Mark Jones and Martyn Madden and Scott Quinnell have both overcome knocks from last weekend's Principality Cup win over Neath.
"Neath provided us with great preparation for a tough match last week. We won, but we also know there are lots of areas to improve," added Jenkins.
Llanelli: B Davies; G Evans, M Watkins, L Davies (capt), S Finau; S Jones, D Peel; I Thomas, R McBryde, M Madden, V Cooper, C Wyatt, D Jones, S Quinnell, S Easterby. Replacements: J Davies, A Gravelle, J Cudmore, I Boobyer, G Easterby, G Bowen, M Jones.