Patty Mills
Mills is not the player he was during his heyday with the Spurs. However, there's a reason why the Jazz signed him over still-available free agents, such as Dennis Smith Jr. and Markelle Fultz.
The Athletic's Tony Jones explained why the Jazz added him to the roster.
While Mills is 36 years old, remember that the Heat were playing him actual minutes during the playoffs. They were undermanned, but they played him hoping that he would provide shooting against the Celtics. They were overmatched against the Celtics, but it means something that he got the nod.
With the Jazz, Mills won't be expected to provide what he used to, but he has clearly shown teams that still has something left in the tank. If he still has some juice left, that could be a welcome surprise for the Jazz.