PAUL Johnson has been ruled out of Sunday's trip to Hull KR with a recurrence of a neck injury.

Johnson originally sustained the injury against St Helens in May and was forced off during the first half of the weekend win against Salford.

Vinnie Anderson is also a severe doubt for Wolves' first trip to Craven Park since last season's Challenge Cup defeat, with the Kiwi suffering a slight recurrence of a back problem.

Second bottom Hull KR have lost their last six home games and eighth-placed Wolves could return to the top six for the first time since Easter if weekend results go their way.

But Paul Cullen warned: "We think it's going to be far tougher than the Salford game. Personally I think that Hull Kingston Rovers are in a somewhat false position in the league."

Mark Gleeson is likely to be on the bench in place of broken arm victim Michael Sullivan, while Henry Fa'afili and Simon Grix are options at left centre to replace Johnson. Paul Cullen has suggested that Fa'afili - a winger by trade - will get the nod.

And, as well as occasional stints in the second row, Fa'afili admits he has enjoyed the switch to the centres in recent weeks.

"I love it there because you get more ball," said the Kiwi. "I'm enjoying it in there, especially when you've got a quick winger outside you in Kevin Penny. It makes my job a lot easier!

"It's a big difference, especially in defence. That's something that I'm adjusting to and just talking through."

Fa'afili is currently without a contract for next season and reports have suggested that, although Wolves would like to keep him, Bradford are interested if terms cannot be agreed.

Asked whether he hoped to stay with Wolves, Fa'afili said: "Definitely.

"I'll just see how it goes and hopefully it goes well but I'll leave that to my manager.

"It's still up in the air at the moment but I'm just concentrating on playing well and going forward from there."

Lee Briers' first career appearance against Hull KR could cause family divisions on Sunday. Briers' wife Vicky is the daughter of Hull KR great David Hall but the Wolves skipper is in no doubt who she will be supporting.

Briers has been injured for each of Wolves' three meetings with the Robins in the past two seasons and said: "My father-in-law and Vicky's family will be over there supporting Hull KR so it will be very strange.

"But Vicky will be supporting Warrington. If she doesn't, she'll be getting a taxi home!"