Game 102 lineups: Nats vs. Rockies (Heisey released)

It's a beautiful day for a ballgame. Let's play ... well, you know. Yes, it's a doubleheader day at Nationals Park, with the Nationals and Rockies meeting in their regularly scheduled contest at 1:35 p.m. and then making up Friday night's rainout at 7:05 p.m. And there's no shortage of interesting storylines to come.

The big one for the opener, of course, is the debut of Erick Fedde, who gets promoted from Triple-A Syracuse and will be on a big league mound for the first time in a couple of hours. The organization's top pitching prospect, Fedde's arrival in D.C. was a foregone conclusion at some point this season. It was just a matter of when. And in what capacity.

After spending time as a reliever earlier this summer, Fedde moved back to the rotation at Syracuse, and so he's now getting a chance to pitch in his natural starting role. We'll see whether that continues or not, but for now the focus is one today's start (with 40-50 of the right-hander's relatives and friends expected in the stands).

Fedde is no stranger, having been drafted by the Nationals with the 18th overall pick in 2014. And he and Bryce Harper were classmates at Las Vegas High School. Both are 24 years old. Now the crazy fact: Fedde is making his MLB debut today; Harper is playing in his 750th MLB game.

The Nats had to do some roster maneuvering to do before submitting lineup cards. Needing to clear a spot on the 40-man roster for Fedde to be added, the club has released Chris Heisey. Meanwhile, Pedro Severino was optioned to Syracuse but recalled to serve as the 26th man for the doubleheader (which means he'll have to go back down after today).

COLORADO ROCKIES at WASHINGTON NATIONALS
Where: Nationals Park
Gametime: 1:35 p.m. EDT
TV: MASN, Ch. 9, MLB.tv
Radio: 106.7 FM, 1500 AM, XM 187/869, MLB.com
Weather: Sunny, 79 degrees, wind 7 mph in from left field

NATIONALS (61-40)
CF Brian Goodwin
2B Wilmer Difo
RF Bryce Harper
1B Ryan Zimmerman
3B Anthony Rendon
LF Howie Kendrick
SS Adrián Sanchez
C Jose Lobaton
RHP Erick Fedde

ROCKIES (59-45)
CF Charlie Blackmon
2B D.J. LeMahieu
3B Nolan Arenado
1B Gerardo Parra
LF Raimel Tapia
RF Carlos Gonzalez
SS Trevor Story
C Ryan Hanigan
LHP Kyle Freeland