There you go, he's in the 20-man squad. This gets cut to 18 a day before the match.
http://www.superleague.co.uk/news/4576
St Helens 20-man squad: Paul Wellens, Ade Gardner, Matt Gidley, Willie Talau, Francis Meli, Leon Pryce, Sean Long, Nick Fozzard, Keiron Cunningham, Jason Cayless, Mike Bennett, Lee Gilmour, Jon Wilkin, James Roby, Maurie Fa’asavalu, James Graham, Bryn Hargreaves, Scott Moore, Jason Hooper, Ian Hardman
Cunningham rumoured to be injured, Wilkin returning from suspension, Cayless returning from injury...