It was the most discussed topic around baseball this month, and when most Twins pitchers were asked about it, most of them responded in hushed voices.

For many, it's the unspoken fear in the back of their mind. Season-ending elbow injuries have been on the rise this year and there is no proven way to prevent them.

Nine pitchers won a Cy Young Award over the past five seasons and five of them underwent Tommy John surgery afterward. Last year's American League Cy Young winner Gerrit Cole is on the 60-day injured list because of elbow inflammation, and last season's strikeout leader Spencer Strider underwent season-ending elbow surgery.

An alarming number of pitchers requiring surgery to repair their ulnar collateral ligament isn't a new phenomenon. It's been a major issue at all levels of baseball for more than a decade — and it's not improving.

"It's almost a rite of passage to have Tommy John [surgery]," Twins reliever Brock Stewart said. "It seems like at some point in your career, it might happen. I've had it once. I know a lot of the guys in here have had it. It is what it is. It's the worst part of the game, but to say any one thing is leading to it necessarily, I don't know. I don't think anybody knows."

There are theories on the cause for the surge in pitching injuries. Velocity is surely the primary factor. Dr. Keith Meister, a leading surgeon who operated on injured Twins pitcher Anthony DeSclafani last month, blamed pitches designed to create the most horizontal movement like sweepers for the recent rise. Dr. James Andrews, another leading surgeon who recently retired, told MLB.com his research showed the Tommy John ligament doesn't mature until age 26.

Tony Clark, the head of the players association, released a statement tying pitching injuries to the pitch clock. MLB issued a subsequent statement emphasizing the long-term trend of pitching injuries and it cited an unpublished study from Johns Hopkins that there was no evidence the pitch clock caused more injuries.

"Everybody is trying to have the biggest breaking ball, the hardest breaking ball," Stewart said. "Everyone is trying to throw 100 mph. With that, injuries happen. It's part of the game. Throwing a baseball at 50 mph is already bad for your arm. You're supposed to throw balls underhand like softball pitchers do."

Reliever Griffin Jax added: "I think it's unfair to say the pitch clock had nothing to do with it. I don't agree with MLB's stance on that."

There is no simple solution. Teams want pitchers who throw the hardest and possess the best breaking balls because those are the pitchers that typically have the most success. It's a trend that extends to college programs and high schools, and there has been a concerning uptick in the number of amateur pitchers who require elbow surgery.

"I was never an overpowering pitcher in the minor leagues," said Twins starter Pablo López, noting his fastball was 89-90 mph at the beginning of his minor league career. "My body grew stronger and bigger, and I was able to touch 94, 95, 96 mph. That really opened my eyes. Obviously, if you have raw stuff, more doors will be open. When players know more doors will be open, then everyone strives for that."

Teams have tried different methods to build up young pitchers. The Miami Marlins, as an example, were seemingly cautious with 20-year-old starter Eury Pérez last year. They sent him to the minor leagues for a month to limit his workload despite his big-league success, and he still required Tommy John surgery this spring.

López grew up in a league that didn't allow pitchers to throw breaking balls until they were 15 or 16 years old, much later than most youth leagues. He required Tommy John surgery after pitching 66 innings in his first minor league season at 17 years old.

"It could happen at any point to anybody," López said. "You could be the most cautious person and the most cautious organization, and sometimes things just happen."

Twins pitchers receive a biomechanical report after each of their outings except for the few stadiums that aren't equipped with the technology. The report includes, López said, the length of their strides, how fast their upper body rotates after their lead foot touches the ground and the power created by their shoulder.

It can help pitchers monitor trends with their mechanics and potentially flag something after outings.

"The biggest thing I try to do with that is make my mechanics as repeatable and consistent as possible," Jax said. "If you have consistent mechanics, you're not putting yourself in a bad spot at any point in the delivery."

All pitchers have arm care routines before and after games to reduce their injury risk. López maintains a 90-minute body routine before he throws daily, which he says can be monotonous and mentally taxing, but necessary to remain healthy.

Jay Jackson, the 36-year-old Twins reliever, was told a callus formed over his ulnar collateral ligament in his elbow — "I think I got lucky in that aspect," he said — and he thinks that helped him avoid Tommy John surgery in his career.

"It's our game. We're trying to protect it the best we can, but we're losing a lot of our top guys right now," Jackson said. "There has to be something done to try to fix that. I don't know if it's an organizational thing or an MLB thing. We need to see realistically why this is happening because you can't have this many guys — especially this many guys of that caliber — going down as consistently [as they] have been. Something is up."