I've been watching the Memphis/Clippers game and one of the players that really stands out to me is Tony Allen. He's a guy that play great defense and can guard multiple positions, knock down open shots, moves well without the ball, finishes at the rim, and doesn't need any plays run for him. If I had a team I would absolutely love to have him playing for me.
Chris Singleton has all the tools to be a terrific defender. He's long, athletic, has great hands to strip the ball (a very under rated aspect of great defensive players), and moves his feet well. Singleton has a much higher upside but for now I think it would serve him very well to watch Allen and see how he operates. A player like that, especially if they can knock down open 3s, can be a key piece for a contending team.