With Fernando Cruz, the Yankees have seen the kind of regression and now injury that they hoped — and arguably needed — to avoid when they did not add (and actually subtracted) from their bullpen at the trade deadline.

The normally reliable and high-octane righty, who entered play on July 19 with a 2.20 ERA and has pitched to a 5.93 ERA since, was shelved with right elbow discomfort Wednesday even before the Yankees had pored over his MRI exam results and knew the severity.

“We’ll see what we have and then attack it from there,” manager Aaron Boone said of Cruz, who was dented again in Tuesday’s loss and has created an even larger void in the Yankees bullpen.

David Bednar, Paul Blackburn and Brent Headrick have been a remarkable trio (but there are workload concerns for each). Tim Hill has had his struggles but been overwhelming against lefties, so he also is likely a fixture for a playoff roster.

Beyond those four relievers, though?

“There’s a couple of spots semi up for grabs now with some guys going down and some opportunities created,” Boone acknowledged before playing the Astros in The Bronx.

Out of contention are Camilo Doval and Jake Bird, who were shipped out at a trade deadline that was expected to see bullpen reinforcements but did not. Now out of contention is Kervin Castro, who pitched well (one run in 6 ⅓ innings) before being sidelined by right elbow neuritis that might require surgery, Boone said, which prompted the righty to be shifted to the 60-day IL.

In contention for important October innings out of the bullpen are:

Clarke Schmidt: Recovering from Tommy John surgery, the righty is attempting to complete a comeback that would finish in the Yankees bullpen rather than rotation.

Schmidt, whose journey back to the mound had been paused by a forearm issue, threw a live batting practice Tuesday that should launch him into a rehab assignment.

Given the different elbow, different role and the care required — Boone said he is “not necessarily expecting” Schmidt to graduate to pitching on back-to-back days this year — Schmidt is difficult to count upon, but the Yankees have liked what they have seen.

“He looked really good [Tuesday],” Boone said. “I’m excited where he’s at.”

Ryan Weathers/Will Warren: One back-end starter had long been assumed to be converted to relief by the end of the season, and Weathers’ recent flexor strain simplified the decision. Weathers is in the beginnings of a no-throw period that is expected to last two to four weeks, and if he can begin building up on the shorter end of the spectrum, he would almost certainly become a significant bullpen piece.

Warren remains in the rotation, but his downturn and his standing (he would not receive a playoff start) at least puts him in the bullpen discussion.

Angel Chivilli: The hard-throwing righty had begun to assert himself as a valuable piece before an Aug. 3 blowup, an ensuing demotion and then an IL stint with what Boone had referred to as “some posterior elbow stuff.”

But Chivilli, who had owned a 0.57 ERA in 14 games before allowing six runs in an inning to the Cardinals, has begun a throwing program and remains an option.

“So far, so good,” Boone said. “So we’ll see.”

Luis Gil: On the way back from a shoulder injury, the former AL Rookie of the Year is being built up as a reliever, and his fastball velocity has ticked up in shorter bursts.

In his first four outings with High-A Hudson Valley and Triple-A Scranton/Wilkes-Barre, Gil had thrown 6 ²/₃ scoreless innings in which he allowed four hits, walked three and struck out eight.

“It’s going pretty well,” Boone said. “I feel like his strike throwing is well. The outings I’ve seen, it looks like the fastball is playing. So we’ve been encouraged with what we’ve seen so far.”

Yerry De los Santos/Ryan Yarbrough: Somewhat overlooked because of their usage — De los Santos in spots of lesser importance and Yarbrough more of a long reliever — both have performed for a team that could grow desperate.

Michael Fulmer/Justin Topa/a veteran to be named later: Fulmer and Topa, veteran righties in their 30s, have been signed and quickly activated this month, going from free agents to potential pieces of a team with World Series aspirations.

Or they could be DFA’d tomorrow as the club keeps searching. The Yankees will want to quickly find out what the new, old arms can do.

“They’re probably going to jump in the deep end,” Boone said. “It’s that time of year. And the reality is on any given day … they’re going to find themselves in leverage situations.

“We like some of the traits that some of these guys have and excited about some of the guys we brought in that are going to get an opportunity to try and grab a role.”