DALLAS -- Right-hander Hector Rondon's latest setback has officially cost him a spot on the Indians' roster.

On Tuesday at the Winter Meetings, Cleveland designated Rondon for assignment, clearing a spot on the club's 40-man roster for the recent re-signing of center fielder Grady Sizemore. Rondon will likely be sidelined for at least six months due to a right elbow injury.

"We're hopeful that he'll be able to pitch at some point next year," Indians general manager Chris Antonetti said. "But we're not certain exactly the time frame for recovery. We're hopeful it's six to nine months."

Renowned arm specialist Dr. James Andrews performed surgery on Nov. 15 to repair a fracture within Rondon's elbow. It is the same joint that required Tommy John surgery in August 2010.

This past season, the 23-year-old Rondon returned to the mound for a pair of outings (three total innings) for Class A Mahoning Valley. After the regular season, Rondon made five relief appearances for Caracas in the Venezuelan Winter League. His winter league stint came to an end on Nov. 5.

Only a couple of seasons ago, Rondon was considered one of the promising young arms in Cleveland's farm system. The righty enjoyed a rapid ascent from Class A Kinston to Triple-A Columbus between 2008-09, when he went a combined 22-16 with a 3.49 ERA and 282 strikeouts over 291 1/3 innings.

Antonetti said it is currently unclear whether Rondon's future with the organization will be as a starter or reliever.

"Right now, it's probably too early to assess that," Antonetti said. "I think we need to see how he progresses through the rehab process and then determine what's in his best interest from there. It's unfortunate, too, because he's a great kid. He's got a lot of ability. It's just his elbow hasn't cooperated."

If Rondon clears waivers, he will head to Minor League camp with the Indians during Spring Training.

Removing Rondon from the roster vacated a spot for Sizemore, who was signed to a one-year contract worth $5 million on Nov. 23. The 29-year-old center fielder can make as much as $9 million, if he meets all the performance incentives included in his deal.

Cleveland's roster is currently at capacity, so subsequent moves would be required in order to add any more players on Major League contracts. The Indians remain in the market for offensive help -- possibly at first base -- and the team might be on the lookout for more outfield and pitching depth.