WASHINGTON -- Reynaldo Lopez, the Nationals' fifth-ranked prospect, according to MLBPipeline.com, will make his Major League debut on Tuesday night against the Dodgers, manager Dusty Baker confirmed after Sunday's 2-1 loss to the Pirates.
To make room on the roster for Lopez, the Nationals placed left-handed pitcher Sammy Solis on the 15-day disabled list with right knee inflammation, retroactive to July 8, and right-hander Abel De Los Santos was claimed on waivers by the Reds on Tuesday.
Lopez, 22, has made 16 starts this season between Double-A Harrisburg and Triple-A Syracuse, where he has combined for 109 strikeouts in 87 1/3 innings with a 3.19 ERA. He looked impressive at the Futures Game in San Diego a week ago, retiring all three batters he faced while throwing as hard as 100 mph.
The Nationals chose Lopez to start in the vacant rotation spot created when Joe Ross landed on the disabled list with shoulder inflammation. Right-hander Lucas Giolito, MLBPipeline.com's top overall prospect, had filled that spot, but the Nationals believe he needs more work in the Minors on his breaking ball. Baker considers Lopez a similar arm to Giolito and said the Nationals have lined the two up to pitch on the same day to give them flexibility to start either one if Ross remains on the DL for an extended period of time.
The club is hoping Solis, who has been one of the Nats' most reliable relievers this season with a 2.43 ERA in 25 appearances, won't have to miss an extended period of time.
Jamal Collier covers the Nationals for MLB.com. Follow him on Twitter at @jamalcollier. This story was not subject to the approval of Major League Baseball or its clubs.