After sitting out the 2018-19 NBA season, Johnson, 38, revitalized his career through 3-on-3 professional hoops and is now fighting for the 15th and final roster spot with the Pistons.
"My body's feeling great. This is probably the toughest part of training camp," Johnson said following Day 3 of Pistons camp at Michigan State. "It's a lot of running and conditioning, but if you come into camp already in shape, you can get through it. I didn't have any problems.
"It's been fun for me, but I haven't had a break in the last six months. But it's been fun. The process has been amazing for me and I'm just thankful for the opportunity."
The seven-time NBA All-Star last suited up during the 2017-18 season, playing for the Utah Jazz and Houston Rockets. He has reentered the NBA picture after a dominant effort in the 3-on-3 ranks, becoming the first Big3 player to land an NBA deal.
Whether he makes the team or not, that alone makes this training camp invitation a success from his perspective.
"That was another reason why I thought it was very important for me to take this opportunity, because those guys in the Big3, a lot of them anyway, have hopes to at some point to be able to get back in the league," Johnson said. "So I just wanted to let everyone know that it's possible just to get to this point. I mean, I'm not even all the way on the roster, but to get to this point, get your foot in the door. Then whatever you do from that point, it's up to you."
Pistons coach Dwane Casey says conditioning hasn't been an issue for Johnson, who's also showing his teammates an even-keeled level of professionalism -- with minimal expressions, even after big plays.
For a Pistons team that finished 41-41 last season, with a first-round playoff exit, that certainly helps.
"It's been really good. I don't even look at Joe for what his age is," Casey said. "He's getting up and down the floor, he doesn't miss repetitions, he's doing all the drills. So he's doing an excellent job."
Since the Big3 launched in 2017, numerous ex-NBA players and personnel have participated, including Jannero Pargo, who is now an assistant coach for the Portland Trail Blazers. Pargo sees Johnson opening doors for other Big3 players to show that they still have what it takes.
Ice Cube couldn't be any happier.
"Joe respected the game and found himself back in the NBA. He played in the Big3 for the love of high-level competition on the highest stage in the summer," Ice Cube told ESPN. "I really enjoyed watching him play this year, and he's an example to all potential players what's really possible. It can happen if you do yo thang in the Big3."