So when Chamberlain threw a fastball to the backstop with two outs, Sizemore was ready. And it was his frantic dash home that imbued new life into the Tribe and sent the towel-waving sellout crowd into a piercing frenzy.
"Very exciting," he said.
In all, Sizemore went 2-for-4 with a triple and two walks in the Cleveland's 2-1 victory over New York in Game 2 of the American League Division Series.
But it was his furious sprint home, a play that so encapsulated Sizemore's relentlessly all-out style, that will long go down as one of the most memorable plays in one of the greatest games in Cleveland's playoff history.
For seven innings, the Indians had missed shot after shot to get on the board. The Tribe led off five of the first seven innings with hits. Sizemore even led the sixth inning off with a triple.
Not once did the Indians score. And as each opportunity slipped away, more and more life came out of a crowd raring to explode.
The rally stifled in the seventh was especially painful for the Indians. They had put runners on first and second with one out to end starter Andy Pettitte's night, but Chamberlain came in and ended the frame while keeping the Indians scoreless. The man who had given up just one earned run in 24 innings this season struck out Franklin Gutierrez on three pitches and induced a weak fly out from Casey Blake.
With Chamberlain emerging to pitch the eighth and Mariano Rivera, the greatest postseason closer in baseball history, waiting to pitch the ninth, the Tribe's hopes were fading fast.
Yet, then it happened. The bugs swarmed the field, and Chamberlain suddenly wasn't a sensation anymore.
"He was having trouble seeing out there," Yankees manager Joe Torre said.
And after Chamberlain walked Sizemore on four pitches, the decisive sequence was in motion. A wild pitch moved Sizemore to second before Asdrubal Cabrera bunted him to third. But Sizemore remained there when Travis Hafner lined out to first.
Sizemore, who took a secondary lead at third, was looking to take the Indians' struggles in the clutch into his own hands.
"He had already thrown a couple wild pitches," Sizemore said. "So I was going to be ready to go."
It showed when Chamberlain threw a two-out pitch just over the glove of catcher Jorge Posada, and Sizemore instantly darted home.
The problem was, the ball ricocheted off the backstop and directly back to Posada.
"I thought we had caught a bad break," Blake said.
Already committed to run, Sizemore simply put his head down, charged home and cleared his mind.
"I didn't want to slide around the plate or do anything fancy," Sizemore said. "So I just went straight at [Chamberlain]."
And though Posada's toss to the burly reliever beat him, Sizemore slid straight through and under Chamberlain's tag.
Sizemore leapt up and pumped his fists. It just may have been the most emotion the Tribe's understated center fielder has displayed in his career.
But who can blame him? If not Friday night, when?
"It's definitely exciting," Sizemore said. "We gained some momentum. We've put ourselves in a good spot."