Johnson, 39, is a seven-time All-Star and was a 2009-10 All-NBA third-team selection. He averaged 16 points per game over his career and averaged 20 or more points per game five times in his career.
His last NBA appearance came with the Utah Jazz and Houston Rockets in the 2017-18 season, averaging 6.8 points across 55 games. He signed with the Detroit Pistons in 2019 but was cut before the season.
Johnson also won a BIG3 title and the league's MVP in the 2019 season with the Triplets.
As for Milwaukee, the team has an open roster spot as it looks to win a title this season. The team has fallen short in each of the last two seasons despite being the top seed in the Eastern Conference both times and Giannis Antetoukounmpo being the MVP in each campaign.
The Bucks retooled their roster this season, adding Jrue Holiday in a massive offseason trade and bringing aboard P.J. Tucker ahead of the trade deadline. Whether that's enough to help the team catch teams like the Philadelphia 76ers and Brooklyn Nets in the Eastern Conference remains to be seen.
Johnson wouldn't bridge that gap, though he would potentially be a decent depth piece off the bench for the Bucks.