Path to Washington: Melancon was drafted by the Yankees in the ninth round in 2006. He was traded to the Astros at the 2010 Trade Deadline in a deal for Lance Berkman, traded again to the Red Sox in December 2011, then traded a third time to the Pirates in December 2012 in the deal that netted Boston Brock Holt. After 3 1/2 seasons in Pittsburgh, Melancon was traded a fourth time to the Nationals before this year's Deadline.
Trophy case: Three-time All-Star (2013, '15-16). Trevor Hoffman National League Reliever of the Year in 2015. Setup Man of the Year (GIBBYs) in 2013. Member of the 2009 World Series champion Yankees.
Famous feat(s): Led the Major Leagues in saves with 51 in 2015. Represented MLB in the 2014 MLB Japan All-Star Series. Pitched for the USA Baseball Collegiate National Team in 2005.
You might not know: While many MLB relief pitchers have converted from starting roles, Melancon has never once started a game in his professional career, Majors or Minors. He's fine with that -- he said he thinks that if he started, he'd have to spend more time preparing than actually playing.
"Relieving is fun for me, being able to participate on a nightly basis," Melancon said. "I love coming into a tight game. The game is on the line and it can come down to one pitch. That's pretty exciting to me."
Six degrees of Willie Aikens: Melancon's first professional baseball experience was pitching in Hawaii Winter Baseball in 2006. He appeared in four games for the West Oahu CaneFires. The Yankees also sent a couple of other prospects to West Oahu who would end up making it to the Major Leagues, Joba Chamberlain and Ian Kennedy.
Bread and cutter: Melancon's signature pitch is his cutter. He drew inspiration from watching Mariano Rivera when he was in the Yankees' organization, but the pitch really took off for him in Pittsburgh in early 2013 thanks to a throwing session and chat with catcher Russell Martin.
"He threw a couple, and I was like, 'Are you kidding me with this cutter right here?'" Martin said. "'This is a pitch you throw every once in a while? No, no, no. You need to get good at throwing this one pitch. It's pretty much a gold mine.'"
No smiling in baseball: Melancon's cutter isn't the only thing he took away from watching Rivera. He also keeps a poker face on the mound like Mo, according to his wife, Mary Catherine. "Mark is very passionate," she said. "He wants to win as much as anybody, but I know he's just not going to make a big scene. That's just how he is. He watched Mariano when he was coming up with the Yankees and really liked how he was just calm out there. Even when he finishes a save, sometimes he still looks very serious. I tell him, 'Mark, smile when you're done.' And he's like, 'No. I'm still thinking about something.'"