It was a nauseating sight. With two outs in the top of the sixth inning on Saturday night in Nashville, Athletics righty Jarrod Parker was making his fourth rehab start in the final stage of his attempt to return from March 2014 Tommy John surgery. But his 0–1 pitch went some twenty feet wild, followed by Parker leaping into the air, grabbing his surgically repaired elbow and crumpling to the ground in front of the pitcher’s mound. The medial epicondyle in his pitching elbow—the place where his new ligament graft was anchored to his humerus bone—had fractured, ending his comeback attempt, likely his season and quite possibly his career.

Parker is just 26 and a former first-round draft pick, and he was arguably Oakland's best pitcher in 2012, the year in which the A's surprised everyone by stealing the American League West from the Rangers in the final series of the season. Parker was the Athletics' Game 1 starter in the Division Series that year and projected to be a key part of their rotation for the remainder of the decade. But in the middle of spring training in '14, Parker complained of tightness in his forearm, leading to the discovery that his right ulnar collateral ligament was damaged. Despite undergoing Tommy John surgery in October 2009 while still in the Diamondbacks’ organization, the righthander would need a second ligament replacement.

Power Rankings: Cardinals, Dodgers battle for top spot; Royals up to No. 3

Parker was one of a number of young starters to require a second Tommy John surgery last spring, joining the Braves' Kris Medlen and Brandon Beachy, who had the surgery in March, and the Padres' Cory Luebke, who had it in February. The Diamondbacks' Daniel Hudson also had the surgery for a second time the year prior. Of those five, Parker had been on the most aggressive schedule of rehabilitation, making his first minor league rehab start two days shy of 13 months after his second surgery.

Luebke, Medlen and Beachy, all of whom had their surgery earlier than Parker, have yet to pitch in any actual games this year. Medlen, now with the Royals, just started throwing live batting practice last week. Beachy, now with the Dodgers, isn’t expected to reach that stage for another couple of weeks. They and Luebke, still with the Padres, are on schedule to return to their teams around midseason. As for Hudson, he made his first rehab appearance last August—13 months, two weeks and four days after his second surgery—but his rehab consisted entirely of single-inning outings. When he re-joined the D-Backs last September, it was as a short reliever.

Indeed, there is little evidence that an elbow that has been subject to multiple Tommy John surgeries can hold up under the rigors of starting pitching. The pitcher with by far the greatest success as a starter following a second TJ is the Yankees’ Chris Capuano, who has made 105 major league starts since having his second ligament replacement in May 2008. Next on the list is Taiwanese lefty Hong-Chih Kuo, who made 14 spot starts for the Dodgers amid a brief major league career as a lefty reliever, all of which took place after his second Tommy John surgery in '03. Still just 33, Kuo hasn’t pitched in the majors or a top-level Asian league since '11.

• CORCORAN: Picking early leaders for MVP, Cy Young, ROY races

As for Capuano, 15 months and four days elapsed between his second Tommy John surgery in May 2008 and his first rehab start in August 2009, and he didn’t throw more than two innings in any of his six rehab appearances over the remainder of the '09 season. Still, he dealt with elbow inflammation in spring the next year and didn’t make his first full-length start after the surgery until April 27, 2010, 2 1/2 weeks shy of the two-year anniversary of his second surgery.

Yankees' Michael Pineda looks like an ace with 16 strikeouts against Orioles

Hudson, who on Sunday became just the eighth pitcher ever to make a major league start after having a second Tommy John surgery, has made a similarly gradual return. After facing no more than five batters in any of his appearances last year, Hudson opened the 2015 season in the bullpen, throwing just one inning in five of his first six appearances and maxing out at nine batters through his first nine before finally drawing a spot start on Sunday, eight days shy of 23 months after his second surgery. That start lasted all of 3 1/3 innings and 56 pitches. With Archie Bradley set to return from the disabled list on Saturday, Hudson will be returning to the bullpen, which thus far is the only place pitchers other than Capuano have found success following a second Tommy John surgery, with the Royals’ Jason Frasor and the Tigers’ Joakim Soria among the best examples there.

pitcher second tommy john games started since Chris Capuano May 15, 2008 105 Hong-Chih Kuo Spring 2003 14 Darren Dreifort July 9, 2001 10 Jose Rijo Early 2001 9 Randy Wolf Oct. 30, 2012 4 Shawn Hill June 30, 2009 4 Victor Zambrano May 15, 2006 4 Daniel Hudson June 18, 2003 1

Still hoping to add his name to the above list is 27-year-old former Blue Jays prospect Kyle Drabek, who had his second surgery three weeks before Hudson’s. But, having recently been removed off the White Sox 40-man roster, Drabek seems no closer to his next major league start than his last in June 2012.

Indians' historically bad defense at root of Cleveland's awful start

It worth noting here that, upon his return to starting in the major leagues, Capuano’s fastest pitch was a sinker that averaged less than 89 miles per hour. Among the other pitchers on the above list, Rijo, Wolf, Hill and Zambrano all averaged below 90 mph with their fastest pitch after their second surgery. Parker, whose fastball averaged nearly 94 mph in 2012, had reportedly reached 93 mph in his rehab appearances. That’s not a particularly alarming speed: Kuo, Dreifort and Hudson all threw harder after their second surgery. But those three all had much longer time recovery periods and spent most of their post-surgery time pitching in relief. Dreifort, after having his second surgery in July 2001, didn’t return to the mound until spring training in '03, more than 19 months later. Even still, after ten starts and sixty relief appearances, his career was over. The timing of Kuo’s second surgery is harder to pin down because it occurred in the minor leagues, but he missed all of the '03 season, didn’t return to game action until June 2004 and totaled just six innings in three appearances in the first two years following his surgery.

• CHEN: Can Dee Gordon turn his hot start into a breakout season?

All of that strongly suggests that the A’s were far too aggressive in their schedule for Parker’s return. That’s not to say that Parker’s elbow would have held up even after a longer recovery period, or that he ever would have returned to his former promise. Still, his injury on Saturday has exposed the idea of his being a contributor just 15 months after a second Tommy John surgery as an expectation with no basis in reality. In fact, given just how gradually Capuano, Hudson and Kuo were brought along after their second Tommy John surgeries—as well as the brevity of the returns of the other pitchers on the above list—one wonders if even the roughly 19 months allotted to Medlen and Beachy will be enough to allow them to contribute, either.