Neil Warnock is delighted to have tied Tom Lees down on a new four-year contract. The 21-year-old defender has pledged his future to the Whites by penning a long-term deal.Lees has more than 100 Football League appearances under his belt, many of those came during loan spells at Accrington Stanley and Bury.He was, however, handed his Leeds debut in 2011/12 and ended the campaign as a first-team regular. Warnock was delighted with the standard of Lees' displays after he inherited the managerial reins at Elland Road in February and had no hesitation in handing the highly-rated defender a top-up to the deal he penned in September 2011."Tom was probably the one bright spark at the back," Warnock told the club's official website."He's made individual errors and he's got to learn, but he's improved his all round game to such an extent that he was one of the first names on the team-sheet. I can't give him a bigger compliment than that."I've told him there will be plenty of competition at the back next season because I am looking to bring in defenders, but he has every attribute."Tom's a great lad, he's Leeds through and through and I see him having a great career here."