The NBA free agency period has already featured a number of surprises, but the most improbable potential signee of the summer is a 61-year-old grandfather once drafted by the San Antonio Spurs. (No, Tim Duncan’s not that old.)

Calvin Roberts, who has been practicing his jump shot and eagerly awaiting a call from an NBA team, was drafted by the Spurs in the fourth round of the 1980 draft. (Duncan was only 4 at the time.) While Roberts, who played his college ball at Cal State Fullerton, never played a game in the NBA, the 6-foot-8 power forward also never let go of his NBA dream.

“This has always been a passion of mine,” Roberts told “Good Morning America” on Friday. “To be able to get into the NBA and enjoy the experience being there, I’m excited, I’m really am looking forward this year at pushing myself to the max, and I believe this year, this is my year.”

Roberts played several years overseas, but he’s determined to play in the NBA. The oldest player in NBA history was Nat Hickey, who played two days shy of his 46th birthday in 1948.

“Where there’s a will, there’s a way,” Roberts’ wife, Noemi Lucero, said.

“If God’s willing, I’ll get into the summer camp and show them I’ve still got talent there,” Roberts said. “The Spurs, I hope they take me to a mini camp and I’ll get a little better there. Veteran camp is where they’re going to make you or break you and that’s my goals.”

Spurs General Manager R.C. Buford has a keen eye for talent, and Gregg Popovich would probably welcome another grandfatherly figure on the San Antonio bench, but Roberts will have to show more than he did while bricking more shots than he made at the end of his interview on “Good Morning America.”