New York Mets relief pitcher Bobby Parnell walks to the...

New York Mets relief pitcher Bobby Parnell walks to the dugout after being taken out of the game when he allowed the Pittsburgh Pirates to score the winning run during the tenth inning of a baseball game at Citi Field on Friday, Aug. 14, 2015. Credit: Kathleen Malone-Van Dyke

Mets pitcher Bobby Parnell heard the Citi Field crowd turn on him, booing him off the mound Friday night after he faced three Pirates batters.

Parnell entered the game with the score tied at 1 to start the 10th inning. He allowed a line-drive single to leftfield by Chris Stewart on an 81-mph knuckle curveball and got in trouble when pinch hitter Francisco Cervelli grounded a single to leftfield.

A mound visit didn't help as Gregory Polanco singled to center on Parnell's next pitch, a 91-mph fastball, to drive in pinch runner Starling Marte with the go-ahead run. Parnell wound up being charged with two runs and took the loss as the Mets lost to the Pirates, 3-2.

"I think today was just a matter of trying to do too much," said Parnell, who was replaced by Carlos Torres after the three hits. "It was a big spot and putting a lot of pressure on myself trying to be too fine. I feel like when I try to get too fine, I give up those little weak hits. You live and you learn."

Parnell returned to the Mets on June 13 after missing 14 months while recovering from Tommy John surgery. The righthander is 1-2 with a 4.82 ERA in 182/3 innings.

Entering the day, Parnell had put together five scoreless appearances since allowing three runs against the Padres on July 30.

"I thought he was going to be fine and he just didn't make the pitches he needed to make," manager Terry Collins said before deflecting blame to the offense. "What you're seeing are days the arm's got it and days it doesn't. There's nothing that can signal when that might be. Bobby's had a couple bad outings, but for the most part, he's pitched very good for us."

Parnell said this season has been like a roller coaster but that he feels fine physically. Asked about his harsh send-off by the vocal crowd, he said the "true fans" supported him.

Collins also was surprised to hear booing, he said, but acknowledged that it's part of the game.

"The fans are caught up in what's going on and they hate losing -- we all do," he said. "You just shrug and realize that happens."