Sheffield United: Blades refuse to be drawn into an auction for Ipswich Town's Martyn Waghorn

Sheffield United will not break their budget to sign Martyn Waghorn, manager Chris Wilder has warned, despite fears the centre-forward could be destined for Derby County unless officials at Bramall Lane up their initial bid.

Waghorn, one of Wilder's leading transfer targets, has been the subject of a £5m offer from United after claiming 16 goals and 11 assists in the Championship last term.

But with Ipswich Town valuing the 28-year-old at nearly double that amount, County are prepared to step into the breach with a package thought to be worth around £3m more, although sources in the East Midlands report it contains numerous performance-related incentives.

Reiterating his desire to recruit Waghorn, Wilder said: "We've got a structure here and it's important we don't ignore that. It's there for a reason and we've got to be sensible, we can't just throw money around like some others."

Wilder, who has described United's proposal as "very good", has been chasing Waghorn for the past two months but was dismayed when news of his approach became public. Clearly several parties involved in the negotiations have a vested interest in encouraging an auction and, while United are understandably keen to maintain good relations with all of them, they are unwilling to play ball by going toe to toe with County. Frank Lampard, Wilder's opposite number at Pride Park, today struck a £5m deal for Peterborough striker Jack Marriott.

Waghorn, previously of Rangers, is reportedly keen on a move away from Portman Road but has not submitted an official transfer request.

Although United are continuing their search for more signings ahead of next weekend's meeting with Swansea City, Wilder's squad building plans received another boost after it emerged Simon Moore is poised to extend his stay in South Yorkshire. The goalkeeper, a second-half substitute against Inter, has been the subject of interest from West Bromwich Albion and is set to become a free agent next summer.

"We're in discussions with Simon," Wilder, who unveiled David McGoldrick earlier this week, said. "We're close and hopefully we'll have something to say about that in the next few days."