Johnson, 40, hasn’t played in the NBA since 2017-18, when he appeared in 55 games combined for the Rockets and Jazz. He appeared in training camp with the Pistons in 2019, but was waived before the season.
He most recently has spent time in the BIG3, winning two MVP awards. Overall, he has appeared in 1,276 regular season NBA games and 120 playoff games.
The Celtics currently have seven players in health and safety protocols heading into Wednesday’s home game against the Cavaliers. They also signed C.J. Miles (story) and Justin Jackson (story) to hardship deals earlier this week, as the league marches on despite all of its missing regulars.