GOODYEAR, Ariz. -- Grady Sizemore isn't going anywhere, after all.

Sizemore informed the Indians on Friday morning that he has decided to pull out of his commitment to represent the United States in the World Baseball Classic because of soreness in his left groin. The Indians passed that information along to Bob Watson, Major League Baseball's vice president of on-field operations, and Phillies center fielder Shane Victorino was tabbed to replace Sizemore on the U.S. roster.

In a news conference at the Indians Player Development Complex, Sizemore told reporters he first felt the groin soreness a little more than a week ago, while fielding fly balls in the outfield. He played in the Tribe's first two Cactus League games to test out the groin and felt the soreness after each game. Now that he has backed out of the Classic, Sizemore will stay out of exhibition action until the injury heals.

"It's very disappointing," Sizemore said. "[Playing in the Classic] is something I was looking forward to doing. I was excited to compete and play for my country. But I'm not doing them any good to show up with an injury, and I'm not doing my team any good to try to battle through an injury for three weeks then come back still hurt. I didn't want to fight through an injury that could possibly get worse."

If anybody seemed a lock to make it to and through the Classic, it was Sizemore. The American League Gold Glove- and Silver Slugger-winning center fielder has to be peeled out of the Tribe's lineup on those rare days he's given off. To him, missing a game is an uncomfortable, almost out-of-body experience.

But Sizemore plays the game with such unshakable energy that he exposes himself to the risk of injury, and that risk was considered too great to take at this early stage.

"With the way Grady plays, he only has one gear," manager Eric Wedge said. "That's the only way he knows. When you're talking about a groin [injury], that can get worse in a hurry."

Sizemore had been expected to leave camp on Sunday. It would have been his first time playing in the Classic and representing his country.

As one of the game's rising stars, the 26-year-old Sizemore, a three-time All-Star, was a natural fit for the U.S. roster. Last year, he became just the 10th AL player in history to notch at least 30 homers and 30 stolen bases in a single season.

Sizemore isn't the first high-profile member of the Indians to decide against playing for Team USA. Reigning AL Cy Young Award winner Cliff Lee had been invited to participate but opted not to because he wanted to stay in his normal Spring Training routine.

The Indians have eight players from their organization heading off to the Classic, including four from big league camp. Right fielder Shin-Soo Choo already left camp to represent Korea, and left-hander Rafael Perez (Dominican Republic), third baseman Mark DeRosa (U.S.) and catcher Damaso Espino (Panama) are leaving Sunday. From the Minor League side, left fielder Nick Weglarz (Canada) and right-handers Sung-Wei Tseng and Chen-Chang Lee (Chinese Taipei) are also leaving.

It is not yet clear how long Sizemore will be out of action. The Indians will take advantage of the extended spring schedule to give him as much rest as necessary.

"We're going to have to pull him back," Wedge said. "He won't play in games for a little while here. We'll see how the treatment goes and work off of Grady. We have enough time in camp to where we can give him the time he needs to work in the right direction. But it's all going to work off the treatment."

Sizemore said he's never dealt with this particular injury before. Because he has been commuting to the Indians' facility from his Scottsdale, Ariz., home since November, he was asked if he perhaps pushed himself too hard to be ready for the Classic.

"I did speed up the process this offseason as far as training and getting into camp," he said. "You get tweaks and pulls every now and then, especially in Spring Training. But I can't say it was because I trained differently or not."