Dallas Cowboys middle linebacker Sean Lee has one year left on his current contract. Lee’s one of the best players on the Cowboys roster so signing him to a long-term deal would seem likely. Cowboys executive vice president Stephen Jones was asked Thursday about the franchise looking into giving Lee a contract extension. “Historically, we look at guys going into the last years of their contracts,” Jones said, “Sean is going into the last year of his contract, so that’s probably something we’ll look at.” The Cowboys are at their best defensively when Lee is on the field, something that occurred during only six games last season. Lee had his season-ended in Week 7 when he tore ligaments in his right big toe. If Lee stays healthy throughout the 2013 season it’s likely that he’ll lead the club in tackles and earn a trip to the Pro Bowl. Lee led the Cowboys in tackles [105] and interceptions [4] in 2011, his second year in the league. But signing him might not be as simple as some might think. The Cowboys would probably like to also extend new contracts to Dez Bryant, Tyron Smith and Bruce Carter in the not so distant future. “Everybody affects everybody,” Jones said. “We don’t just look at what our cap is in 2013. We have to project out and see what that does to 2014, 2015.”