The Dallas Mavericks and Minnesota Timberwolves continue to exchange proposals on an Al Jefferson trade and moved closer to a deal over the weekend, according to sources with knowledge of the talks. But the sides still don't have a done deal, sources said, despite the fact that Dallas has somewhat eased its stance on the inclusion of Erick Dampier's lucrative non-guaranteed contract in a trade for Jefferson. It also appears that the Mavericks have some fresh competition for Jefferson from the Utah Jazz. Sources told ESPNDallas.com that the Mavericks would ultimately consent to part with Dampier's $13 million contract in a Jefferson swap if the Wolves also agree to take on the contracts of DeShawn Stevenson and Matt Carroll, thereby lessening the financial hit Dallas faces by absorbing the three years and $42 million remaining on Jefferson's deal. But Minnesota has thus far resisted Dallas' attempts to include Stevenson and Carroll in trade discussions and would insist on two conditional future first-round picks if those players are included, sources said. Sources said the Wolves, furthermore, are also receiving sustained interest in Jefferson from the Jazz, who have a trade exception created by their recent Carlos Boozer sign-and-trade with Chicago that is believed to be large enough to take in Jefferson's contract. It is unclear, though, what other assets Utah would be willing to part with in a Jefferson deal after losing Boozer and Kyle Korver in free agency and with a decision looming on whether to match the five-year, $34 million offer sheet Portland has tendered to Jazz guard Wesley Matthews.