What seemed like a major sacrifice by a rookie outfielder turned into the ultimate insult to injury.

Tyler Callihan, who just made his MLB debut for the Reds last Wednesday, broke his left forearm running into the wall in the left field corner to make what initially seemed like an inning-ending catch in the bottom of the third Monday night.

But while Callihan reacted in pain, the ball fell out of his glove moments after the catch, and he flung his glove off.

The ruling was a catch did not occur, and Braves first baseman Matt Olson came all the way around for what became a two-run inside-the-park home run.

Callihan, 24, was set to return to Cincinnati from Atlanta Tuesday to undergo surgery.

“He’s such a good kid, you feel terrible for him,” Reds manager Terry Francona said.

The Reds challenged the call; replay confirmed that Callihan touched the ball in fair territory, and it was deemed he did not possess the baseball long enough for it to be considered a catch.

“There’s no good way to explain it,” Francona said. “The kid is running full blast trying to do everything he can to save runs.”

Blake Dunn replaced Callihan in left field for the remainder of the Reds’ 4-0 loss.

The Reds selected Callihan in the third round of the 2019 draft out of the Providence School of Jacksonville.

In 24 games with Triple-A Louisville this season, Callihan has a .303/.410/.528 slash line with four home runs, 12 RBIs, 19 runs and six steals.

He was 1-for-6 with an RBI across his first four MLB appearances.

It’s unclear how much time Callihan will miss with the injury.