5. Oklahoma City Thunder
You might be wondering why I added the Oklahoma City Thunder to this list considering they weren't even in the playoff picture last year. However, based on how a lot of their young talent did last season and the fact that they did get some good players in the draft, I wouldn't want to play them in the playoffs.
Josh Giddey will return this season as their starting point guard. Giddey has surprised a lot of folks in the couple of years he's been playing in the NBA. I even thought he was going to win Rookie of the Year when he first entered the league.
Another player that the Mavericks will need to be concerned about in the playoffs is Chet Holmgren. He missed the entirety of this past season with an injury, but he'll be ready for a big-time bounce back. After watching him take on the Mavericks at Summer League this summer, I wouldn't want to be the center guarding him in the post.
Oklahoma City also added rookie Cason Wallace a the trade with the Mavericks in the NBA Draft. He looked good in Vegas against the Mavericks as well. The Mavericks should not want to go up against the Thunder if they are healthy around playoff time.