A mysterious, similarly mustachioed Mike Maddux lookalike took in Monday's Nats-Rockies game

Mike Maddux is the Nationals' pitching coach. After a 15-year pitching career, he moved into coaching and now mans the dugout alongside Dusty Baker and the rest of the Nats' staff. He's also the brother of Greg Maddux, eight-time All-Star, four-time NL Cy Young Award winner, and all-around MLB icon. 
Mike and Greg are not twins. There are no other Maddux brothers. And yet, somehow, this guy showed up in the stands (decked out in Nats gear, mind you) during Washington's 5-4 win over the Rockies at Coors Field on Monday night:

Again, Mike does not have a twin brother, and the guy above is not Greg. So who ... is ... he? 
Remarkably, this isn't even the first time this season a Nats game has featured a doppelganger in the stands, after a Bryce Harper clone was spotted earlier in the summer. 
The mind boggles ...