San Antonio Spurs forward Tim Duncan has enjoyed one of the most impressive careers in NBA history, but it might be coming to a close.

Adrian Wojnarowski of Yahoo! Sports reported Monday that the five-time champion is “leaning strongly toward retirement.”

Duncan has played 19 seasons for the Spurs since they drafted him No. 1 overall in 1997. He has led San Antonio to NBA titles in 1999, 2003, 2005, 2007 and 2013.

Even if Duncan retires, the Spurs still should be a legit championship contender.

Veteran guards Tony Parker and Manu Ginobili are expected to return for another season, as is the core of the team in superstar swingman Kawhi Leonard and power forward LaMarcus Aldridge. Gregg Popovich arguably is the best head coach in the league.

Thumbnail photo via Soobum Im/USA TODAY Sports Images

Thumbnail photo via Dec 5, 2015; San Antonio, TX, USA; San Antonio Spurs power forward Tim Duncan (21) shoots the ball over Boston Celtics center Jared Sullinger (7) during the first half at AT&T Center. Mandatory Credit: Soobum Im-USA TODAY Sports