When NBA free agency begins at midnight July 1, Brooklyn Nets star guard Deron Williams will be choosing from a two-team list that only features the Nets and the Dallas Mavericks, according to sources close to the situation.

Sources told ESPN.com on Saturday night that, while this summer's No. 1 free agent remains "up in the air" about which team he'll ultimately chose, Williams already has made the decision to narrow his list of potential destinations to those two franchises.

Other teams, including the Phoenix Suns, Portland Trail Blazers and Houston Rockets, had been hoping to lodge their own bids for Williams once free agency begins, sources said. The Los Angeles Lakers, likewise have continued to express interest in a sign-and-trade package built around Pau Gasol for Williams, sources say, despite the Nets' longstanding insistence that they have no interest in Gasol and would only consider such a move if they were getting back All-Star center Andrew Bynum, whom the Lakers have not made available.

Sources say Williams, in any case, already has instructed his representatives to advise any team that calls starting at 12:01 a.m. July 1 that he intends to either re-sign with the Nets or return to his hometown with the Mavericks after a glittering high school career in the Dallas area.

The Nets have expressed confidence all season in their ability to retain Williams, pointing to the team's forthcoming move to Brooklyn, increased off-court marketing opportunities for Williams with a team bound for New York and the fact that Russian billionaire owner Mikhail Prokhorov can offer a contract one-year longer than Dallas can worth nearly $100 million.