DENVER -- Not only are four of the Rockies’ five expected starting pitchers on the injured list -- with two gone for the year because of Tommy John surgery -- but the situation with their top prospects is ominous enough that general manager Bill Schmidt turned to football terms.

“On football when they call it, you get 15 yards -- it’s called piling on,” Schmidt said.

When the second half of the season started on Friday, the Rockies placed on various injured lists:

• Double-A right-hander Gabriel Hughes, last year’s 10th overall Draft pick and their No. 6 prospect per MLB Pipeline.
• Single-A Fresno righty Jordy Vargas, the team’s No. 11 prospect.
• Fresno righty Jackson Cox, last year’s second-round Draft pick and the team’s No. 12 prospect.

All are being evaluated for elbow injuries. Hughes at 21 and Vargas and Cox at 19 are young enough that their innings were being closely monitored, anyhow. But all are hurt enough for the Rockies to seek answers before deciding the next step.

This means three of Colorado’s top four pitching prospects are currently out, with only right-hander Jaden Hill (No. 9), a second-round Draft pick in 2021, enjoying good health. This is a system that has seen left-handed prospects Ryan Rolison (the Rockies’ top pick in 2018), Sam Weatherly (a third-rounder in 2020) and Helcris Olivarez (a gem from the Latin American program) undergo shoulder surgeries since the end of last season. None is active.

In the Majors, Opening Day starter Germán Márquez has undergone Tommy John surgery, and manager Bud Black announced Friday that Antonio Senzatela will have the same procedure. Also, lefty Kyle Freeland is out with a dislocated right shoulder, and righty Ryan Feltner is out with a fractured skull.

“As [manager] Buddy [Black] would say, that’s baseball -- maybe not the good part of baseball,” Schmidt said.

It’s the same for any team with injury problems -- and data suggests the pitcher injury bug will hit everyone.

A recent article in the Tampa Bay Times referred to a survey by writer and database curator Jon Roegele. On June 28 -- just a random day -- the database showed that 39.7 percent of pitchers on Major League active rosters and 15- and 60-day injured lists had undergone Tommy John surgery at some point in their careers.

Sometimes, you’re really unlucky, as the current Rockies can vouch. But when Colorado made the postseason in 2017 and ‘18, it was led by a staff of starters whose arms were mostly clean.

The issue is full of theories. They pitch too much starting in childhood. They don’t throw enough as pros. The increase from once a week in college to once every five days can trip some pitchers up. There’s too much emphasis on velocity. Subtle grip changes can create an optimal flight path, but they also put ligaments in positions contrary to how the individual pitcher’s arm works.

“We’re not doing anything differently, and historically we’ve been one of the lower organizations in terms of elbow injuries,” Schmidt said. “I heard since the ‘16, ‘18 or ‘19 Draft, 60 percent of pitchers have had arm or shoulder injuries. We’ve been real diligent with all our pitchers. Sometimes things happen.”

Injury attrition is one of the reasons the club has selected 30 pitchers in the last two MLB Drafts.