Paul Deacon is out of the Bulls’ Good Friday derby shake-up against Leeds Rhinos.

The skipper had exploratory knee surgery yesterday after continuing to be hampered by a problem that has plagued him throughout the start of Super League XIV.

Boss Steve McNamara said: “The surgeon’s had a look inside and hopefully it’s just some more cartilage that needs removing. Deacs has been struggling for a while and has been a bit unfortunate with that knee.

“It’s not serious by any stretch of the imagination but it has needed to be treated, as in the last couple of games it has created a few problems.”

Deacon, 29, saw the end of last season dogged by an injury to the same knee and went under the knife for a minor operation over Christmas.

The former Great Britain scrum half has played every match so far but – like the side in general – hasn’t found his best form.

He has been in the wars, going off with head injuries against Huddersfield and Castleford, while opponents have clearly targeted him over the last fortnight when he has crucially been found wanting defensively a number of times.

Deacon – who chalked up his 2,500th career point in France on Sunday – is certain to miss the Easter Monday trip to Wakefield and possibly the visit of Warrington Wolves next Friday. It leaves McNamara with a half-back dilemma as he bids to turn his side around after their devastating Challenge Cup loss against Catalans and slow start to Super League.

Options include moving centre Paul Sykes to stand-off, or Aussie veteran Steve Menzies switching from the pack, with current No 6 Ben Jeffries shifting to scrum half.

Second-row David Solomona could return to bolster the squad against the champions, having been missing since opening day with a dislocated shoulder.

Meanwhile, McNamara blasted his players behind closed doors for their awful capitulation on Sunday.

The Bulls conceded a staggering 40 points in just 35 second-half minutes to see all their good work undone against Catalans.

They had led 26-0 and missed just four tackles in the first half but that shot up dramatically towards 30 as players alarmingly fell off challenges.

Their defence, which crumbled late on at Castleford, was awful and McNamara said: “The players know from myself that that is just not acceptable.

“We can’t continue to do that. A mistake is only a mistake if it is repeated and I feel we have repeated some of ours two weeks running now.

“It is criminal. Our missed tackles are hurting us badly.

“It’s everyone’s responsibility to fix that up but on the day, players have to go out there and make those tackles.”