“I’m just glad we got the personnel and bodies to cover,” Baker, who referred to Romero’s ailment as a strain, said.

Romero said he initially felt the discomfort on the second pitch he threw to Giancarlo Stanton, a change-up that Stanton took for a strike. Romero, however, stayed in for the rest of the at-bat and struck out the slugger with a 98 mph fastball before motioning to the dugout. A team trainer then came out to check on him. Romero threw a pitch to test his forearm out and immediately exited.

“I was unsure, so I tried to throw a fastball to see if I still felt it again, and I did feel it again,” Romero said through an interpreter while his left arm was wrapped. “That’s why I stopped.”

The 26-year-old Romero said the only injuries he has dealt with before have been back problems, including a back spasm episode recently that he was able to get through with some rest without a stint on the disabled list. The hard-throwing Dominican was one of the Nationals’ most reliable relievers before their recent bullpen overhaul and had a 2.05 ERA over his previous 24 appearances before Wednesday. Overall, he’s posted a 3.99 ERA in 45 games. His 46th appearance might have to come after a visit to the DL.

“I’m not sure yet what’s going to happen,” Romero said. “I know I’m going to rest it tomorrow, and it depends how I feel on Friday. They might make a decision. I know they’re going to be cautious with it, but it depends how I come back on Friday and how I feel.”