"I don't know what happened," Ruiz said. "I started to feel something in my chest and thought I was going to throw up. I drink Red Bull during the game. Maybe I had one too many."
With Ruiz's health an issue, Coste remained at designated hitter, rather than be lifted for lefty Matt Stairs or Greg Dobbs. As the team's backup catcher, Coste went 0-for-3 against lefties Scott Kazmir and J.P. Howell, then grounded out against Balfour.
"He was having dry heaves and down there coughing," Manuel said. "He's fine now. About the sixth inning, somebody told me I better check on Chooch. He might be sick. So I thought we better leave Coste in the game."
Running mostly on adrenaline, Ruiz stayed in the game -- going 0-for-3 with an RBI groundout and a walk -- and he was in Thursday's starting lineup. The 29-year-old, who has started every postseason game, said he would've fought anyone who tried to pull him from the contest.
"I wasn't going to come out for any reason," Ruiz said. "I felt something in the fifth or sixth inning, and they kept asking me, 'Are you OK?' and I kept saying, 'Yeah.' It didn't matter how many times they asked. I feel a lot better today. I'm ready."
After batting .313 (5-for-16) in the National League Championship Series against the Dodgers, Ruiz played in his first World Series game on Wednesday.
"I couldn't wait to get on the field and catch that first pitch," he said. "I'll never forget that moment. When I caught the first pitch from Cole [Hamels], it was an unbelievable feeling."
Ken Mandel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.