After taking the field for the eighth and warming up in right, Myers walked into the dugout with assistant athletic trainer Paul Harker. The Rays announced shortly afterward that Myers was receiving IV fluids after he exited the game.
Myers struck out swinging against Red Sox reliever Junichi Tazawa to end the seventh inning, and he said he first started to feel cramps when he swung through for strike three. He said after the game that he had never experienced a similar injury, but he figured he'd be ready to play in Game 4 of the American League Division Series on Tuesday at 8:30 p.m. ET on TBS.
"With that, he should probably be fine by tomorrow. It's kind of a dehydration thing," manager Joe Maddon said. "That's what I got [from head athletic trainer Ron Porterfield] before I came and walked over here [for the postgame interview]."
Myers, a front-runner for AL Rookie of the Year, has gone 0-for-12 in the ALDS. Jose Lobaton hit a walk-off homer off Red Sox closer Koji Uehara in the ninth inning while batting in Myers' spot.
Adam Berry is a reporter for MLB.com. Follow him on Twitter at @adamdberry. This story was not subject to the approval of Major League Baseball or its clubs.