No. 4: Isaac Okoro
The Toronto Raptors have a major question mark to answer on their roster, and that's who will defend opposing guards? Immanuel Quickley is a fine team defender but needs to be the worst defender in a lineup. Scottie Barnes is more of an interior defender and rover. Bruce Brown is the answer if the Raptors keep him around, but he doesn't seem long for the team.
Enter Isaac Okoro, perhaps the best perimeter defender on the market. He can lock up ball-handlers full-court or shadow them in the halfcourt, getting skinny over screens and using quick hands to disrupt dribbles or passing lanes.
To his credit, Okoro has improved as a shooter and has always been a heady cutter and finisher. He once looked like a defense-only young player who may accordingly flunk out of the league, but he has improved every year and now looks to be in line to land a large payday.
The barrier to signing Okoro is that he is a restricted free agent, and the Cleveland Cavaliers are likely to match any reasonable contract offer. If they pull off a series of moves that prevent them from paying Okoro, however, the MLE seems to be about right for his market.