If you think this doesn’t look like such a worrisome matter, you might be right. The defense doesn't look that bad with the starting five on the court, and Doc Rivers could fix it a little bit. The problem is these facts could become really worrisome by the playoffs. Because Philadelphia and Boston, two teams Milwaukee will probably have to beat to get to the Finals, are terrible matchups for Lopez.
Celtics are the team to beat in the East, and they are because of their offense, which is mainly built on their shooting and the great spacing it provides. The key piece that masters that shooting and that spacing is Kristaps Porzingis as a stretch five.
Milwaukee played Boston pretty amazingly in the first half of their last game, but the pick & pop plays being lethal in a potential matchup is still something to worry about. There’s simply no way for Lopez to defend that play. He just cannot switch, because he cannot take down a player like Jaylen Brown 23 feet away from the basket, and he’s always going to be late to contest the Porzingis or Horford 3-pointer. And even if Porzingis is not having his best season as a shooter, you cannot live with that shot for an entire series.
Philadelphia isn’t a good matchup either, in this case because of Maxey's sheer speed. He’s insanely fast, which could be a problem in the transition game but also in the pick & roll. He has such a good touch that he will punish Lopez over and over if he drops and give him the floater, but will also overpass him and get a free layup if Lopez is too far away from the basket.
However, this is not such a strong case because of Embiid, who would probably have to be taken by Giannis Antetokounmpo the whole game if Lopez gets traded. More on that next.