There is a strong likelihood that Friday's midnight deadline for contract extensions for first-round picks from the Class of 2011 will pass without a new deal for reigning NBA Finals MVP Kawhi Leonard, according to league sources.

Sources told ESPN.com this week that Leonard and the San Antonio Spurs, despite more serious discussions between the parties in advance of the Halloween buzzer, are unlikely to come to terms during this extension window, setting up the 23-year-old to become a restricted free agent in July.

‎Negotiations, however, do remain alive going into the final day for at least three other prominent 2011 first-rounders: Golden State's Klay Thompson, Minnesota's Ricky Rubio and Cleveland's Tristan Thompson.

Kawhi Leonard, the 2014 Finals MVP, likely will become a free agent at season's end after failing to come to terms with the Spurs during the extension window, sources said. Andy Lyons/Getty Images

Leonard has been billed as the Spurs' future face of the franchise for some time -- long before he emerged as the star of San Antonio's five-game destruction of the LeBron James-led Miami Heat in the 2014 NBA Finals -- and had his agent, Brian Elfus, in San Antonio this week to negotiate with Spurs officials.

But sources say that San Antonio prefers to wait until the offseason to address Leonard's future in the name of maintaining maximum financial flexibility.

That strategy does come with an element of risk, since Leonard is sure to attract max offer sheets of varying contract lengths on July 1, his first day as a restricted free agent. But the Spurs would have the right to match any offer Leonard gets next summer in that scenario and would be able to do so with a better feel about how much longer stalwarts Tim Duncan and Manu Ginobili want to keep playing. If the Spurs were to extend Leonard's contract now, and then either Duncan or Ginobili -- or both -- decides to retire, San Antonio's cap space to replace them would be lessened significantly.

A contract before Friday's deadline is thus considered far more likely for Klay Thompson, Rubio and perhaps even ‎Tristan Thompson.

Sources say that the Wolves and Rubio have been in advanced negotiations for the last few weeks that are likely to lead to an extension. Thompson and Golden State, meanwhile, have been in serious talks for some time after the Warriors backed out of long-running Love trade talks with Mi‎nnesota this offseason in order to keep Thompson.

Six members of the Class of 2011 already have received extensions: Cleveland's Kyrie Irving, Denver's Kenneth Faried, Orlando's Nikola Vucevic, Charlotte's Kemba Walker and Phoenix Suns twins Markieff and Marcus Morris.

Other well-regarded members of that draft class who appeared unlikely to land deals as of Thursday night, thus heading for restricted ‎free agency, include Oklahoma City's Reggie Jackson, Chicago's Jimmy Butler, Milwaukee's Brandon Knight, New York's Iman Shumpert and Miami's Norris Cole.‎

According to multiple media reports, Utah and big man Enes Kanter decided ‎Wednesday to back away from the negotiating table to allow Kanter to be a restricted free agent in July. Jazz guard Alec Burks remains eligible for an extension before the deadline.