Rockies medical director Dr. Thomas J. Noonan was scheduled to do his official evaluation Monday night, but based on MRI readings, he let Ottavino know the operation is the recommendation.
"It's unfortunate, but if it's true and if everything is consistent, I'm going to see Dr. Andrews to be evaluated Wednesday as my official second opinion," said Ottavino, 29. "And if he agrees, then I'll just get the surgery right then and there, and I plan on coming back next year strong as I can."
John Axford, an experienced closer, will slide into the ninth-inning role.
Ottavino, making $1.3 million in his first year of arbitration, saw an uptick in his velocity during the second half of last season, hitting 97-98 mph on his fastball at times. According to MLB.com pitch-tracking data published by FanGraphs, Ottavino averaged career highs of 94.9 mph on his two-seam fastball and 95.2 mph on his four-seamer this season.
The effectiveness was stunning. Ottavino struck out 13 against two walks and three hits in 10 1/3 innings.
''It's certainly a tough day," Rockies manager Walt Weiss said. "We had an idea there was something on in there. He's going to get another opinion, but it's tough. 'Ax' will close. Obviously, when he's unavailable, we'll go to [40-year-old Rafael Betancourt, who has been effective this season after missing last year because of Tommy John surgery]. We'll have some pieces out there."
Return time from Tommy John surgery is unpredictable. Target dates start around one year but can vary based on setbacks or whether a pitcher is a starter or a reliever.
Ottavino knows it could be worse. As a prospect in the Cardinals' chain in 2010, he missed much of the season at Triple-A Memphis with a right shoulder strain but handled the issue with rehab.
"I was a lot more scared years ago when I thought I was going to have to have shoulder surgery, because that's pretty much a death sentence," Ottavino said. "This is not really as much of a death sentence, and we have four or five guys who've had it, and lots of pitchers I've played with -- Adam Wainwright, guys like that. Hopefully, I'll be the next to be a success, come back and be myself again."