Joe Johnson hasn't played in the NBA since the 2017-18 season, so it came as a bit of a shock to him when the Boston Celtics came calling.

Not that Iso Joe has given up on returning to the NBA, but he admitted he didn't have high hopes of stepping foot on an NBA court and play ever again. Fortunately, he managed to stay in good condition, thanks to his son who has kept him in the gym to work out.

“I wouldn't say give up, but I didn't have high hopes. My son's 14, so he keeps me in the gym. We work and work and work, and I always talk to him [and say], ‘Just work. Even when you can't see what's next, you just gotta continue to work,” Johnson said, per Tim Bontemps of ESPN.

Joe Johnson signed a 10-day deal with the Celtics via hardship exception amid the rising cases of COVID-19 in the team. Five Boston players–including Al Horford, Jabari Parker and Josh Richardson–entered the league's health and safety protocols in recent days, forcing Brad Stevens and Co. to find a replacement player.

Johnson is expected to provide a scoring boost off the bench for the Celtics, but more than that, it appears he is ready to become a stabilizing force on the roster and provide some mentorship to both Jaylen Brown and Jayson Tatum.

Iso Joe is also relishing the opportunity to come back to Boston and play for the Celtics, the team that drafted him in 2001 to start his NBA career.

“Yeah I think, for me, it would be nice to come out here, perform well and have fun,” Johnson added. “Enjoy this little process that I've got. Because I could probably walk away from the game, but I love it so much, man. Like I said, my son keeps me going, and me and him have so many battles — one-on-one battles, shooting games, all those type of things.

“So I've always got things to fuel me and keep me motivated. It's just preparation meets opportunity at this point.”

Entering Wednesday's game against the Cleveland Cavaliers, the Celtics are 15-16 on the season as they continue to struggle to string wins together.