Hidden under the fervor of Kevin Durant's free agency decision to head to Golden State, a future Hall of Fame icon could also be leaving, for good. Yahoo Sports reports that San Antonio Spurs icon Tim Duncan is "leaning strongly," toward walking away.

One of the NBA's all-time icons - San Antonio Spurs center Tim Duncan - is leaning strongly toward retirement, a decision that would end an illustrious 19-season NBA career, league sources told The Vertical.

Duncan has left team officials, close associates and friends with a strong belief he's preparing to make an announcement in the near future on his departure, sources said.

Source: Sources: Tim Duncan 'leaning strongly' toward retiring - Yahoo Sports.

Duncan turned 40 this year, and was left nearly unplayable against the Thunder, though obviously that's not as much of a concern now. Several times during their series vs. the Thunder, Duncan would stand alone at the free-throw line during OKC's introductions, absorbing the moment. After being blocked in the Thunder's Game 6 victory over the Spurs, he ambled to the bench slowly.

Durant activated his player option for next season at around $6 million, and Manu Ginobili announced earlier this week that he would return for his 15th season. There's ample reason for Duncan to return, but he may simply have reached the end of his time as an NBA player.

Meanwhile, with that news hovering, the Spurs are reportedly finalizing a deal with Pau Gasol to replace Duncan before the Warriors snatch him up. Gasol obviously would fill much of the role Duncan did, and would struggle as much if not more on the defensive end.

If Duncan retires, it caps a run of 19 seasons, all with more than 50 wins, five championships, and one of the greatest runs for a franchise and single player of all time. As well as the Spurs are set up for the future with Kawhi Leonard and LaMarcus Aldridge, the Spurs won't be the same if the Big Fundamental hangs them up.

Tim Duncan could walk away from the NBA. USATSI