I'm a fan of Paul Millsap, but I don't really want him back. He's too old to be a long term piece for this developing team and he will cost too much money.
I'd gladly bring back DeMarre Carroll though. Junkyard Dog was Atlana's best defender, but could possibly be 4th best in Utah. . . think on that for a bit. He could come in and play SF or SG with Hayward and be Utah's perimeter "stopper" in the playoffs.
The defensive potential for a lineup of Gobert, Favors, Carroll, Hayward and Exum is intriguing, and his improvement as a scorer the past two seasons under Snyder and Budenholzer are impressive. He was the Hawks best player in the playoffs. I love Hood and Burks, but Carroll would be a better starter right now. Then bring Booker, Jingles, Hood and Burks (who we've slid into Trey Burke's current role behind Exum) off the bench. Draft or sign a backup center, and this team is in business.