People close to Tim Duncan were shocked the future Hall of Famer decided to join the San Antonio Spurs as an assistant coach on Monday.

Maybe they shouldn't be.

According to Marc Stein of The New York Times, Duncan becoming an assistant coach for San Antonio was his idea for the most part.

Yet I also heard more than once in Monday’s conversations that this, amazingly, was Duncan’s idea for the most part. He knew (Gregg) Popovich was struggling to fill the last open spot on his bench staff and made himself available because he sensed that Popovich needed him.

Tim Duncan is the best player in Spurs franchise history and arguably the best power forward in NBA history. Now, Duncan will be back on the Spurs bench, this time as an assistant coach helping Popovich lead San Antonio in the rugged Western Conference.

Duncan loves basketball, but it's going to be strange to see him in a suit on the bench coaching guys. Nevertheless, players such as DeMar DeRozan and LaMarcus Aldridge have to be thrilled Duncan is joining the coaching staff. The two All-Stars can learn a lot from Duncan.

In 1,392 games with the Spurs, Duncan averaged 19.0 points, 10.8 rebounds, 3.0 assists and 2.2 blocks while shooting 50.6 percent from the field. He won five rings, two regular season MVP awards and two Finals MVPs.