#5: Keldon Johnson
Spurs small-forward Keldon Johnson is set to make the most of any player on the team next season, but he still counts as underpaid. Johnson led the team in scoring last season by averaging 22 points, which ranked 24th in the NBA. Yet, thanks to his contract extension, which he signed last season, he will make just $20 million.
Some could argue that he is a "good stats, bad team" player, but he did show improvement as a driver and finisher at the basket, drawing fouls. His scoring last season was also in line with his average during the post-all-star break of the 2021–22 season, when Johnson helped lead the team to the play-in tournament, suggesting that it wasn't a fluke. That year, he shot nearly 40% from three on high volume, but he regressed last season after starting out the year red-hot.
If his outside shooting can improve to the mean, he can make another big offensive leap next season, particularly with Victor Wembanyama there to draw attention away from Johnson. As it is, there are only two dozen players who averaged 20 points last season, and Johnson will make less than every single one of them. That certainly points to him being underpaid, and there is reason to believe that he can be even better next season.