WASHINGTON -- While they have a spot in their starting rotation free, the Nationals wanted to take the opportunity to see what their young pitching prospects could do in the Majors. It started with Lucas Giolito, baseball's top prospect, earlier this month and continued with the debut of hard-throwing right-hander Reynaldo López on Tuesday night.
For stretches during his Major League debut in Tuesday's 8-4 loss to the Dodgers, Lopez showed flashes of the talent that has advanced him so quickly through the Nationals' organization. But the Dodgers were able to lock in on his fastball from the start of the outing and drive him out of the game after he allowed six runs on 10 hits in 4 2/3 innings, although he finished with nine strikeouts.
The first batter to greet Lopez -- the Nationals' fifth-ranked prospect -- in his Major League career was Dodgers second baseman Chase Utley, who deposited the third pitch of Lopez's career into the seats in right-center field. Later in the first, Joc Pederson roped a two-run single to give the Dodgers a 3-0 lead. Chris Taylor began the second inning with a double and scored later in the inning on an Utley single.
"I felt like the location of the fastball was very good, but they were anticipating fastball and jumping on that fastball right away," Lopez said through an interpreter. "So after the first few innings, it seemed like I started mixing up my pitches better and it worked out."
With that better mix of his pitches, Lopez began to settle down in the middle innings. He retired eight consecutive batters at one point -- six via the strikeout. His nine strikeouts were the second most in a debut in Nationals history, behind only Stephen Strasburg's 14-strikeout performance in his electric debut in 2010.
"This is a young kid, pretty good delivery, and there was a lot of swing-and-miss from our guys," Dodgers manager Dave Roberts said about Lopez. "The change didn't really play today, but he was throwing the breaking ball to left-handed hitters and right-handed hitters for a strike when he needed it, for the most part. It's hard to pitch behind in the count and really not locate the fastball, but certainly this kid has a bright future and great stuff."

Nats general manager Mike Rizzo said before the game that it was no coincidence that Lopez and Giolito were both scheduled to start on the same day as Joe Ross, currently on the disabled list with shoulder inflammation. Ross threw a 35-pitch simulated game before Tuesday's game and will almost certainly need multiple Minor League rehab outings before he is ready to return to the Majors.
So Washington could go to either Giolito or Lopez in order to fill the rotation slot while Ross is sidelined. And Giolito impressed in his debut at Triple-A Syracuse on Tuesday, where he allowed an unearned run in 6 2/3 innings with seven strikeouts.
"I think we're fortunate enough to have three 22-and-younger starters with that kind of ability level that can start for us at any given time," Rizzo said.
Still, despite the up-and-down results, the Nationals liked what they saw in their first impression from Lopez.
"He's young, this is the big leagues, and you're facing big league hitters," manager Dusty Baker said. "But he's very bright, just got to tighten up a few things. I think he'll be here for a long time."