(Jeffrey Phelps/AP)

“It started [Thursday] after the game,” Harper said. “I couldn’t hold food down and stuff. I was throwing up until 2 o’clock in the morning. I played yesterday, was throwing up during the game. I tried to eat again, then threw that up again. Just not feeling well at all. My head is spinning every day. Just not feeling well.”

Harper was originally in the lineup Saturday afternoon. While taking batting practice, he felt lightheaded and “had a dizzy spell,” Johnson said. Harper assumed the dizziness was a by-product of all the vomiting.

Harper visited a doctor at Miller Park, and the Nationals removed him from the lineup in favor of Corey Brown. “I was kind of pissed off about it,” Harper said.

“The doctor said he could be at the end of a little virus or just catching something,” Johnson said.

Still, Johnson said it is “more than likely” Harper, who went 1 for 8 on Thursday and Friday, will play Sunday. Harper would have been available as a substitute if the Nationals needed him Saturday night. “He was again driving people crazy on the bench,” Johnson said.

Harper had not kicked the virus by Saturday, but he was feeling better and is confident he’ll return to action.

“I’m keeping food down, so that’s good,” Harper said. “I’m still a little jittery and whatnot. I don’t see me missing out on anything. I’ll be in there tomorrow.”

More on the Nationals:

Zimmermann is homecoming king in Nats’ win

Box score: Nationals 4, Brewers 1

Harper sits out with stomach virus

Werth unlikely to return by Tuesday