PITTSBURGH (AP) -- Terry Collins had seen enough. After watching the Mets strike out 14 more times in their fifth loss in six games, the manager addressed his team behind closed doors.
There was plenty to talk about.
Jonathon Niese was knocked out in the fifth inning, and the Mets managed just seven hits in a 9-1 loss to Pittsburgh on Sunday in the finale of a three-game sweep for the Pirates.
"We're just not executing," Collins said. "For five years, the effort has never been a question. We've just gotta go back and start doing the little things."
New York has dropped 10 of 14 overall. In tandem with a diagnosis of spinal stenosis for third baseman David Wright and Juan Lagares and Lucas Duda missing Sunday's game, the team is frustrated.
But, to Collins, that doesn't excuse poor play.
"What you try to do is pick the right time to say knock it off," Collins said. "You're big league players, you're the best of the best. Let's just go play like it."
Francisco Liriano (2-4) struck out 12 in six innings for Pittsburgh. The left-hander allowed one run and six hits.
"It was the start he needed," Pirates manager Clint Hurdle said. "It was the start we needed from him."
New York struck out 36 times in the weekend series. Gerrit Cole and A.J. Burnett had 10 strikeouts apiece in the first two games.
Niese (3-5) allowed four runs and seven hits in 4 2/3 innings. The left-hander dropped to 1-5 with a 5.40 ERA in his last six starts.
Andrew McCutchen and Starling Marte homered for the Pirates.
Jordy Mercer's RBI double got Pittsburgh a 1-0 lead in the fourth. The Mets tied it in the fifth on Wilmer Flores' RBI single.
The Pirates chased Niese in the fifth. McCutchen connected for a two-run shot, and Francisco Cervelli had an RBI single.
Niese hung a breaking ball to McCutchen, and the slugger drove it into bullpens in left-center.
"I had a feeling he was sitting on that pitch," Niese said. "I should've stayed away from it. He was looking out there, he wasn't looking in."
Marte hit a three-run shot in the sixth for his ninth homer, lifting Pittsburgh to a 7-1 lead.
Jared Hughes, Tony Watson and Arquimedes Caminero combined to allow one hit in the final three innings for the Pirates.
TIME ON THEIR SIDE
One month and one day ago, the Mets owned the best record in baseball with their 13-3 start. They dropped to 24-21 with Sunday's loss.
"I think there's good baseball yet to be played," Niese said. "There's a lot of season left and it's going to turn around."
As for the manager, there is a touch more urgency when it comes to getting back to playing winning baseball.
"It's not a critical juncture," Collins said. "But we've gotta turn it around now."
Mets: New York returns home to begin a six-game homestand against Philadelphia and Miami. RHP Bartolo Colon (6-3, 4.85 ERA), who turned 42 on Sunday, starts on Monday against Philadelphia RHP Severino Gonzalez (2-1, 7.11 ERA).
Pirates: Pittsburgh continues its eight-game homestand against Miami. Pirates RHP Charlie Morton (hip) makes his season debut against Marlins RHP David Phelps (2-1, 3.21 ERA)
Mets: Lagares missed the game with discomfort in his right armpit and elbow. ... Duda was out of the lineup with a tight right hamstring, which he injured sliding Saturday.
Pirates: Morton has been out while recovering from surgery on his right hip last September.