THERE may be several surprise faces in Warrington Wolves' ranks against Bradford on Sunday in response to Paul Cullen making a blunder.

Wolves' coach took a calculated risk against Wakefield last week by fielding players who were far from fully fit.

The gamble backfired in spectacular fashion as his battle weary troops put in their 'worst performance of the season' and Cullen has learnt his lesson.

So from here on in, he has vowed to only select players who have a decent week's training behind them.

That will put more onus on Wolves' fringe players to step up to the mark and earn their keep but Cullen has confidence in the strength in depth of his 25-man squad.

And with a host of his 'tried and trusted' hampered by knocks, ailments and illnesses, the chances are that Cullen will ring out the changes for Sunday's game against mighty Bradford.

Cullen said: "We got a thumping against Wakefield but there won't be any public flogging of the players on my behalf.

"The poor performance at Belle Vue is entirely my responsibility. I pushed guys out on the field that I shouldn't have done.

"We got away with it the week before and the week before that and for some it was simply a game too far.

"With the benefit of hindsight it was a mistake and one I won't be repeating.

"So if any of my players aren't fit enough to do a decent week's training then they won't take to the field, even if they are adamant they want to aim up and play for the club and its supporters.

"Therefore, there could be a number of changes against Bradford. Some players do not deserve to play after showing a lack of effort against Wakefield and some need a rest after carrying injuries for a while."

Cullen was reluctant to reveal the identities of his walking wounded for fear of them being targeted by future opponents.

But he did divulge the fact that the calf injury which ruled Lee Penny out against Wakefield was a recurrence of the problem which sidelined him for five games at the start of the season.

The full back tweaked the old injury the morning before the game and is considered a doubt for Sunday.

Cullen is calling for his side to 'play smart' against the Bulls. On current form he considers them to be the best team in Super League but he sees chinks in their armour and has been encouraged by the way his players have responded to the Wakefield defeat.

Cullen said: "There has been a very good response since we lost at Wakefield.

"To be fair, we trained well building up to the Wakefield game but training has been even more intensive this week because the guys want to make amends and they are looking forward to playing against Bradford.

"The Bulls are jam-packed with pace, power and genuine quality but we are relishing the challenge.

"To beat them we have to be smart on the way that we go forward, even smarter on the way that we kick the ball and exceptionally honest in the way that we chase it.

"We need to put them under pressure and force them to break."

Russell Smith is set to referee Sunday's game, which kicks off at Wilderspool at 3pm.

He is widely regarded as the best in the business and is unlikely to buckle if Bradford hooker James Lowes applies his trademark intimidation tactics.

Cullen said: "Our discipline must be spot on against Bradford. If decisions don't go our way we have to accept them and keep our mouths shut.

"That is something we didn't do against Bradford in the Challenge Cup earlier in the season and it cost us dear."