The Spurs are in a rough patch right now with three straight losses, including a 129-114 road loss to the Timberwolves in their last game this past Wednesday. 
However, the Spurs still are superior to the Magic. The situation sets up for the Spurs here and there is splendid line value, too. 
The Timberwolves played great in beating San Antonio. It happens. Teams run into a hot-shooting foe who comes in with their "A" game. Minnesota is a very improved team, too. 
The Spurs are not the dominant serious title contender of years past. But they remain a quality team with the best coach in the league, Gregg Popovich. The Magic are getting respect from the oddsmaker based on their last game, which was a smashing, 112-97, home victory versus the 76ers. Note, though, the 76ers were playing their second road game in 48 hours and sat out Joel Embiid. The Magic had been idle the previous two days so the situation set up great for them. 
This game isn't an ideal spot for the Magic. The Spurs are in full stop-the-pain mode. Even with their high scoring effort against the 76ers, the Magic still rank last in scoring and second-to-last in field goal percentage.