Moments earlier, the right-hander tossed a 1-2 fastball that was slightly elevated, and switch-hitter Josh Bell made him pay. Oh watched the ball sail into the stands in left field and the Pirates pour onto the field to celebrate their 5-2 walk-off victory over the Cardinals on Friday night at PNC Park.
"That particular one was a ball up [in the zone]," Cardinals manager Mike Matheny said. "Not exactly where you want to put it."
It marked the seventh time this season that Oh has given up a home run to a left-handed batter, with lefties hitting .363 against Oh in 2017. He only allowed one home run to left-handed batters in 2016.
"The missed pitches are becoming extra-base hits," Oh said through a translator. "It's not that I am struggling against lefties."
But those missed pitches are coming at inopportune times, as the closer situation continues to remain an issue for the Cardinals entering the second half of the season. Oh has had 21 save opportunities this year, while Trevor Rosenthal has had six. Friday night wasn't a save opportunity, but Oh entered in the ninth with the game knotted at 2.
Oh began the frame by surrendering a double down the left-field line to Pirates left fielder Adam Frazier. He induced Josh Harrison to fly out to right field before intentionally walking Andrew McCutchen. Oh then faced the switch-hitting Bell, who capitalized on Oh's struggles against left-handed hitters. It was the seventh home run that Oh has allowed in the ninth.
"I had a good rest [during the All-Star break] and was ready to go," Oh said. "But tonight was not the best start to the second half."
The Cardinals were handed an additional loss in the ninth, when right fielder Stephen Piscotty left the game with a right groin strain. He sustained the injury while fielding Harrison's fly ball, and he was replaced by Jose Martinez, who was called up from Triple-A Memphis on Friday to replace injured Randal Grichuk.
Matheny didn't have a timetable for Piscotty's return.
"He wanted to jog around and see if he was going to be OK," Matheny said. "For it to grab like it did, it's probably not a good idea to leave him in the game at that point, because anything he is going to have to do is going to have to be at full speed at that particular point, so we needed to get him out. The trainers got their hands on him now. We will find out a little bit more later."
Jonathan Toye is a reporter for MLB.com based in Pittsburgh who covered the Cardinals on Friday. This story was not subject to the approval of Major League Baseball or its clubs.