Carlisle United look set for a busy final 48 hours in the transfer window - with Bradford still chasing Charlie Wyke and the Blues understood to be eyeing winger John O'Sullivan.

Bradford still believe they can force through a deal for Wyke despite the Blues appearing to hold out for other offers.

The League One club's manager Stuart McCall has claimed the release clause in Wyke's deal - which they have met with a £250,000 bid - is "black and white".

McCall claimed the Valley Parade club remained "hopeful" of landing Wyke and said his club have "played everything by the book."

Carlisle, though, appeared to be trying to keep the Bantams at arm's length, with manager Keith Curle insisting he expects further interest in the striker before tomorrow's transfer deadline.

That followed hints that the "complicated" nature of Wyke's deal has so far prevented Bradford from sewing up the transfer quickly.

McCall claimed "a lot of people have got involved" in the situation, adding that the matter was being discussed further between the two clubs.

Curle claimed that other clubs - including one in the Championship - were also keen on Wyke, but it remains to be seen whether any further bids materialise.

Curle said: "I'll be surprised if there won't be a few people making calls to the football club to find out where the bidding's at, or individually, as clubs, posting an interest with Charlie."

Carlisle refused to respond to McCall's comments, only saying they do not discuss the detail of individual contracts including clauses, but McCall insisted the delay in Bradford signing the striker was "nothing to do with us".

Wyke scored his 18th goal of the season in United's 1-1 draw with 10-man Barnet.

Curle, meanwhile, plans to revisit some of his own transfer targets today.

They are thought to include O'Sullivan, whose availability alerted United when he was released by Blackburn earlier this month.

The 23-year-old attacking midfielder is understood to have had interest from other clubs but Carlisle are thought to be at the front of the queue.

The Blues will now hope to clinch a deal for a player who was the subject of a bid from Barnsley two years ago.

United last night declined to comment on O'Sullivan, who had several loan spells during his time at Ewood Park, including two with Accrington Stanley.

Curle, though, has said he is determined to bring in new faces before tomorrow's 11pm cut-off - a bid that may be even more urgent following injuries to Shaun Brisley (knee) and Jason Kennedy (groin), both players currently being assessed by physio Neil Dalton.

Curle said: "I'm looking to bring in two, potentially three players. One was very close to getting over the line [for Saturday]. There were reasons why it couldn’t get done for him personally, and there was another one that, from instructions from the parent club, they wouldn’t release the player, but they wanted to further the negotiations on Monday morning.

"It will be a little bit frantic but ideally we will be going for the targets we've identified first and foremost.

"There are a few other players that are not a priority to come straight into the team, but we see them as being progressive for the squad."

Curle has said United's ability to afford new players does not hinge on Wyke leaving, but the manager said he had discussed with the club's hierarchy about spending any extra cash that would "get put back into the pot".

"We've identified targets for different scenarios," he added.

On Saturday's injuries, the Blues boss said: "Shaun Brisley jarred his knee and felt something - he doesn’t know if it's an injury he had previously where he's tweaked a ligament.

"Because of the frailty of our squad, as a precaution we took him off. Jason's had an injection in his groin last week and that's flared up again."

Despite Brisley's injury, Carlisle cannot recall Mark Ellis under the terms of his half-season loan. Ellis started for Forest Green in their 3-2 win at Barrow.