4. Derrick Jones Jr.
Heat fans remember Derrick Jones Jr for his high-flying dunks, most notably winning the slam dunk contest as a member of Miami back in the 2019-2020 season. He received spot minutes during the Bubble Finals run as a lengthy defender, but he could have developed a lot more in the Heat’s system. He is still a streaky shooter, but his natural athleticism and perimeter defense make him a role player that any team would love to have. He's emerged as a core member and starter for a good Dallas Mavericks team this season.
Although Miami’s defense has gotten better since the beginning of this season, it can still be shaky at times. Prime examples include recent home losses to the New Orleans Pelicans and Golden State Warriors. Having someone who can defend multiple positions is another type of player the Heat have needed. Jones is versatile in that category and is similar to Caleb Martin on the defensive end.
Having all three options of Martin, Haywood Highsmith and Jones as defensive options would have created a field day of options for Spoelstra. All of them can guard positions 1-4 at an elite level and are capable of impacting the game offensively, too.