Twins righthander Mike Pelfrey knows exactly why he tore the ulnar collateral ligament in his elbow in 2012 — and he's certain that it wasn't because of overuse during his younger days.

That's become the popular theory to explain the alarming rash of Tommy John elbow ligament-replacement surgeries in the majors this season. According to baseballheatmaps.com, 17 big-league pitchers this year already have suffered UCL injuries that required the surery.

That includes the Tampa Bay Rays' Matt Moore, who decided on Monday to have ligament replacement surgery on his left elbow, an operation that will sideline him for about a year. It doesn't include Twins third base prospect Miguel Sano, a position player. The high since 2004 was 35 in 2012, so the injury is happening at a much higher rate this year.

Dr. James Andrews, one of county's leading experts on Tommy John surgeries, said during a recent interview on Sirius/XM radio that overuse during a player's high school years might be a reason for the increase in elbow tears. Rays manager Joe Maddon feels the same way.

"Sometimes you have to look underneath the surface, and I tend to agree it has a lot to do with youth sports and travel teams and multiple travel teams and kids pitching to win when they're really young and throwing too many pitches," Maddon told the Associated Press. "I think the more recent epidemic, curiously, might be tied to what they're doing before they even get here professionally."

Pelfrey said he believes the reasons extend well beyond teen overuse. Before the 2012 season began, he said he decided to alter his mechanics to see if he could improve his pitches. He sizzled in his final two starts of spring training for the Mets.

"I hit 97 [mph], and it was sinking," Pelfrey said. "I was like, 'OK, this is going to be good!' I go out and had three starts and I was pitching good."

Then came elbow pain, a diagnosis of a partially torn UCL and Tommy John surgery. Pelfrey, who will start Wednesday for the Twins against the Blue Jays, said he never had serious arm trouble before 2012, when he was 28 years old. He believes there's almost an inevitability to elbow problems.

"Eventually it gets to the point where you throw so much it's going to happen," he said. "It's such an unnatural motion."

He's not the only current Twins starter who has come back from Tommy John surgery. Righthander Kyle Gibson said he began "tinkering with my mechanics" while he was struggling in 2011, and that led to him tearing his UCL and needing the surgery.

The Twins have had five major league pitchers undergo Tommy John surgeries since 2004, ranking 20th among all teams: Grant Balfour, Scott Baker, Francisco Liriano, Joe Nathan and Pat Neshek. The Braves lead with 12, which includes Kris Medlen and Brandon Beachy this season. Organization-wise, the Twins were listed with 15 players needing Tommy John surgeries, more than 12 other teams.

In addition to overuse, some believe the increase in using cut fastballs and split-fingered pitches puts extra strain on the ligament, increasing the chances of tears. Tommy John surgery — in which the ulnar collateral ligament is replaced with a tendon from elsewhere in the body — has saved and prolonged careers. But no one has been able to figure out how to limit the injury.

"I think there's a lot of different factors, and a lot of it teams can't control because of what a player has done coming up in high school or in college," said Rob Antony, the Twins assistant general manager. "When he started throwing a breaking ball, did he pitch year-round? There are so many factors ... I just think there's a lot of different stages in a career where they might suffer some of the effects that lead to [surgery]."

Twins work hard at prevention

The Twins have programs in place designed to help reduce the risk of pitchers breaking down. Pitchers on the Twins' rookie league teams generally make one start a week. And the Twins employ a six-man rotation at Class A Fort Myers and Class A Cedar Rapids. More pitchers get a chance to start, no doubt. But it also allows the club to be careful with pitchers who are coming out of high school and college.

"It makes it easier to manage their innings, which helps get guys through the year without being shut down early due to an innings limit," said Brad Steil, the Twins director of minor league operations. "It provides a good transition for high school and college pitchers, who usually pitch once a week in school, and that's over the course of a shorter season than they pitch in pro ball."

During the season, the Twins will have their minor league pitchers skip starts to give them a break. And since there's a seven-day disabled list in the minors, it's easier to be careful with a pitcher who is experiencing soreness by putting him on the DL.

"Even if you think it's not a bad injury you can put them on the DL and give them a break," Antony said, "because when the arm is fatigued, that's one of the indicators that he's a higher risk for injuries."

But despite the best efforts, elbow ligaments continue to tear, and it's happening at any stage of a player's career.

"It's unfortunate," Antony said. "Everybody thought the Braves handled Kris Medlen as well as you could have and he ended up having a second one. Sometimes it just can't be helped. Sometimes things happen.

"I'm not sure if there is a right way or a wrong way. Everyone has their own idea of how to manage it."