"We've got a virus running through the club," Farrell said prior to the game. "We had a couple of guys throwing up yesterday that still played, but because this is persistent since the other night, we want to be sure that he's in a safe place, and we can get to the bottom of it."
The Red Sox had to pull Napoli in the third inning of Thursday's loss to the Orioles due to the dizziness, nausea and light-headedness. It improved a little in the past two days, but Boston's looking for answers.
Farrell said the team's pretty sure this is not concussion-related, but they don't have the final answer just yet.
"He's going to see our internist and then any kind of recommendation they'll make for follow-up, he'll do," Farrell said.
Jeff Seidel is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.