SUNDERLAND will continue to dig in their heels over Patrick van Aanholt despite Crystal Palace firming up their pursuit of the full-back with a bid that could be worth up to £8m.

Palace boss Sam Allardyce is desperate to be reunited with van Aanholt this month, having played a pivotal role in the defender’s improvement over the last 12 months during his own spell at the Stadium of Light.

Palace officials have tabled an initial bid of £6m, with a further £2m of potential add-ons, but Sunderland chief executive Martin Bain was quick to reject the offer.

While David Moyes is aware that any money raised from departures could aid his own attempts to sign players this month, he does not want to lose van Aanholt, who has been one of the Black Cats’ most influential players this season.

Van Aanholt has started all bar two of Sunderland’s league games this term, and even though he has been playing at left-back, his three Premier League goals make him the club’s joint second-highest scorer.

The Black Cats have no intention of selling for less than £10m, but if Palace were to return with a bid that was significantly higher than that, the position adopted by Moyes and Bain could change.

While Jermain Defoe has been deemed untouchable amid interest from West Ham, every other player in the Sunderland squad has their price. For van Aanholt, that would have to be an up-front payment of at least an eight-figure fee.

The 26-year-old has not expressed a desire to leave Wearside, having signed a long-term deal last summer that commits him to the Stadium of Light until 2020.

He grew close to Allardyce last season though, with the former Sunderland boss having helped engineer a marked improvement in his defending, and it remains to be seen whether the news of Palace’s interest has an unsettling effect.

Moyes is likely to address the issue head on when he conducts his weekly press conference ahead of Saturday’s home game with Stoke City tomorrow afternoon, with van Aanholt expected to retain his place in the starting line-up for the visit of the Potters.

While Sunderland do not want to lose the Dutch defender, they are more than happy to wave goodbye to his compatriot, Jeremain Lens, if they can secure an £8m deal this month.

Lens is currently on a season-long loan at Fenerbahce, with his temporary Turkish employers keen to sign him on a permanent basis. Fenerbahce cannot afford to meet Sunderland’s asking price though, with the Black Cats having rejected their offer of a swap deal involving Gregory van der Wiel and Emmanuel Emenike.

That stance has clearly infuriated Lens, with the winger aiming a sly dig at Sunderland by claiming it could be easier for him to leave permanently if the summer if the Black Cats are relegated to the Championship.

“I would like to stay for many years at Fenerbahce, but it’s not just for me to look at,” said Lens. “I hope I could get a signature that will allow me to stay here.

“I do not want to talk about my contract, but many things will be easier if Sunderland drop down. Let’s wait and see.”

Adnan Januzaj is another player who has been linked with a possible move away from Wearside, with the on-loan winger’s agent, Dirk de Vriese, having confirmed he has held talks with French club Lyon.

“Lyon are one of the many French clubs who have recently sounded out Adnan’s plans,” said de Vriese. “Out of respect, we have to listen to everyone. However, the ultimate decision is with Manchester United and we have not heard from them that the club wants to sell Adnan.”