4. Cameron Payne
The journeyman point guard has been respectable as Lillard's backup. He is a steady hand who doesn't make many mistakes and has been shooting well this season (40.3% on threes).
Payne's postseason experience and playmaking could come in handy for Milwaukee in the playoffs, but he has the same issues as the players mentioned above. He is a small, defensively limited player. And those players don't make the biggest impact come playoff time.
Due to Payne's physical and athletic deficiencies, it's hard to play him next to Lillard. This makes his role extremely limited on this team. He will likely be restricted to a 10-minute-per-game role in the playoffs. He could have a larger role on another team looking for pick-and-roll creators off the bench.
The Bucks will be better off if they can upgrade the backup guard position with a tougher and more physical player who can also play next to Lillard if needed.