Luol Deng, the Great Britain player, has turned down a reported $50 million (about £25 million) contract offer from the Chicago Bulls, a deal that would have paid him £100,000 a week over the next five years and catapulted the 6ft 9in forward among British sport’s highest earners.

The 22-year-old, who is considered to be one of the most outstanding young talents in the NBA, is understood to be holding out for the maximum contract available to him under the league’s salary cap regulations – $60 million over five years or £120,000 a week.

The deadline for the contract extension is tomorrow, when the Bulls open the season away to the New Jersey Nets. If an agreement is not reached by then, Deng will become a “restricted free agent” at the end of the forthcoming campaign. That would allow him to negotiate a deal with another club, but Chicago would have first right of refusal – the option of matching any rival offer, thus retaining his services.

Yesterday, John Paxson, the Bulls general manager, was optimistic of signing Deng before the deadline and sought one-on-one talks with the player. Ben Gordon, the Chicago guard who was born in London, is in the same situation and has reportedly turned down an identical deal.