Joe Johnson says he's been living in the gym and staying in shape in case an NBA team comes calling ... telling TMZ Sports he'll be ready to go if a squad needs him for the playoffs.
38-year-old Iso Joe made a hyped return to the Association in October when the Detroit Pistons scooped him up from the BIG3 ... but got cut a few days before the season.
Joe tells us there are no hard feelings with how it went down in Motor City, saying his body wasn't right at the time.
"I was banged up with a lot of injuries, didn't get a chance to really rest," Joe tells us. "So, it kinda hurt me. Which is why I got waived. But, I'm cool with it."
Now, Joe says his body is at "100" and his agent is keeping tabs on teams' interest as the season reaches that time of the year ... but makes it clear he's not gonna beg to get signed.
"I don't think I have to plug myself for that. I think my resume pretty much speaks for itself."
FYI -- Joe is a 7-time All-Star, former All-NBA third teamer and went on to be the BIG3 MVP last year.
"Like I said, if an opportunity comes about and it's worth it and a team is serious, of course I'll jump on that opportunity."
Advice to NBA teams ... HIT ISO JOE UP!!!!!!!