Cubs injury updates: Codi Heuer, Brandon Hughes, Brennen Davis facing surgery recoveries

LONDON — Cubs pitchers Codi Heuer and Brandon Hughes have long injury recoveries ahead of them, with the pair of promising relievers likely out for at least the rest of the season.

Heuer had surgery Friday to repair a fracture in his right (pitching) elbow, and Hughes is set for surgery at the end of the month to address the recurring swelling in his left knee.

Heuer was more than six weeks into a rehab assignment at Triple-A Iowa when he doubled over in pain after a pitch Tuesday.

‘‘We all saw it,’’ president of baseball operations Jed Hoyer said. ‘‘You knew in real time that he’d done something serious. And my heart breaks for him, given how hard he worked to get back.’’

Heuer was nearing the end of his rehab from Tommy John surgery, which he had in March of last year. The Cubs even had extended his rehab assignment to make sure he had honed his command before returning from the injured list.

Now a return before spring training of next season looks unlikely. His reconstructed ulnar collateral ligament is still intact, so strong that the end of his humerus suffered the damage rather than the ligament. He had screws and wires put in to hold everything in place.

While Tommy John surgery has well-tested protocols in terms of a timetable for a return, an injury such as Heuer’s has a less definite time frame. Recovery requires immobilization, which adds a wrinkle to the rehab process.

Hughes, on the other hand, has a chance to return in spring training next year, barring any setbacks. He has been battling swelling in his left knee all season, stemming from a meniscus surgery in 2015. With the cartilage worn down on the lateral side of his knee, he successfully had managed the discomfort until this season.

‘‘He’s never really gotten consistently to where he was last year with mechanics because of his knee,’’ Hoyer said. ‘‘And he’s fought so hard to get out there. He’s such a competitor. But it finally got to a point where we’re just going to keep [taking] one step forward, one step back over and over.’’

Hughes’ procedure involves breaking or cutting the femur above the knee to shift his alignment. That will move the pressure to the part of his knee that still has cartilage.

Davis has surgery

Outfield prospect Brennen Davis had core-muscle surgery last week after missing significant time last season for back surgery.

‘‘It’s tough to see him go through this much adversity, especially back-to-back,’’ vice president of player development Jared Banner said. ‘‘It feels like he hasn’t really had a chance to get in rhythm over a long period of time. But he’s a very resilient guy.’’

Davis was the Cubs’ No. 1 prospect entering last season before having surgery a year ago to address sciatic nerve pain stemming from pressure caused by a vascular malformation. He was out for three months.

The Cubs sent Davis to the Arizona Fall League to make up for lost at-bats, but he left early with a stress reaction in his back.