Kansas City Royals reliever Jake Brentz’s season officially ends with elbow surgery

Kansas City Royals pitcher Jake Brentz turned in one of the best seasons of any rookie reliever in the majors last season, but his sophomore season is now officially over.

On Thursday, the Royals announced that Brentz had left elbow ulnar collateral ligament reconstruction surgery, or Tommy John surgery.

Entering this season, Brentz had been viewed as one of the stalwarts at the back end of the Royals’ bullpen along with right-handers Scott Barlow and Josh Staumont.

Brentz appeared in just eight games this season and struggled to consistently throw strikes before he went on the injured list with a left flexor strain on April 30.

Brentz, 27, went on a minor-league rehab assignment with the Royals’ Double-A affiliate Northwest Arkansas on June 19. However, that assignment was shut down after just two appearances. He did not record an out in his second appearance.

This season in the majors, Brentz posted an ERA of 23.63 after he allowed 14 earned runs on 11 hits and 10 walks in 5 1/3 innings. He struck out nine during that same span, registered a WHIP of 3.94 and opposing hitters batted .423 against him.

Last season, Brentz made the major-league roster out of spring training despite having not appeared in an MLB game.

Among rookie relief pitchers, Brentz ranked first in games (72), tied for second in holds (15), fourth in innings (64) and strikeouts (76), tied for fourth in wins (five), sixth in opponents’ batting average (.197) and K/9 (10.69), tied for eighth in saves (two) and 10th in ERA (3.66).

He proved to be one of the Royals’ most reliable relievers last season and pitched in a team-high 72 games (tied for the eighth-most games in the majors). He also recorded the second-most appearances by a rookie in a single season in franchise history behind Kelvin Herrera’s club record 76 in 2012.

Brentz’s 76 strikeouts were the second-most by a Royals left-hander in a single season, and his 10.69 K/9 ratio was the fourth-best in a single-season by a left-hander in club history.

Last season, Brentz also recorded a scoreless streak of 15 consecutive innings from May 14-June 15.