The Drillers announced after Saturday's game that MLB.com's No. 31 prospect underwent an emergency appendectomy that is expected to end his season.
Pomeranz arrived at ONEOK Field complaining of abdominal pain, according to a source close to the team. After meeting with the trainer, he was taken to a medical center, where he was diagnosed with appendicitis. Pomeranz was transported to another facility, where he had successful surgery and was expected to remain overnight.
Officially traded to the Rockies on Tuesday as the player to be named later in the July 30 deal that sent Ubaldo Jimenez to Cleveland, Pomeranz will miss the rest of the season, the Drillers said.
Major Leaguers Matt Holliday and Adam Dunn also underwent emergency appendectomies earlier this year but were able to return to their teams within 10 days. The situation is different with Pomeranz because pitching puts a greater strain on the abdominal muscles. Additionally, the Rockies likely will play it safe with their new prospect, especially with Tulsa's season concluding on Sept. 5. The Drillers are five games out of a Texas League playoff spot.
Reached for comment on Pomeranz's status, Rockies vice president of communications Jay Alves said, "We're aware of the situation."
After posting a 1.98 ERA across two levels with the Indians, Pomeranz made his Tulsa debut on Wednesday and took a perfect game into the seventh inning. The fifth overall pick in the 2010 Draft ended up allowing two hits over seven shutout frames.
Pomeranz would be the second Top 50 prospect in three days to go down with a season-ending injury. Bryce Harper, MLB.com's No. 2 prospect, strained his hamstring while running the bases for Double-A Harrisburg on Thursday and is expected to be shut down by the Nationals.