The Mets’ lineup has been slumping for a week, Saturday’s starter Shaun Marcum struggled in his debut and reliever Robert Carson was worse. By the time it was over, the Mets suffered a 9-4 beating at the hands of the Phillies and were mired in their first three-game skid of the year.
Marcum (0-1) lasted just four innings in his injury-delayed Mets debut, giving up three earned runs and Carson coughed up five more — including back-to-back homers — in his only inning and was booed lustily by the 29,248 at Citi Field, who saw the Mets fall two games under .500 for the first time this season.
“That’s not what I wanted from a statistical standpoint or helping the team. I wasn’t very efficient with my pitches in the second or third innings,’’ said Marcum. “I’ve got to … make sure next time I’m putting the ball in play a lot earlier in the count and go deeper into the game. … I’ve got to get a lot more efficient, locate and keep the ball down.’’
The Mets demoted Josh Edgin to Double-A yesterday to make room for Marcum, who made his first start after neck and shoulder woes in spring training. But he couldn’t minimize the damage in a three-run third, leaving for Carson an inning later down 3-2, and the bullpen imploded again.
“It’s not like we’re playing terrible baseball. It’s one or two innings that are hurting us,’’ said catcher John Buck, who hit his eighth homer, a solo shot in the ninth. “If we were going out there not putting together good at-bats, or continuously having bad pitching, maybe [I’d worry]. But that’s not the case. It’s the one big inning that’s hurting us.’’
It hurt them again. Lefty Scott Rice was roughed up in the ninth inning Friday, and yesterday Carson, the struggling bullpen’s other southpaw, served up a three-run homer to Domonic Brown and a solo shot to John Mayberry Jr. just a pitch later for an 8-2 hole.
“I missed with my slider up and in, and Brown just hammered it, as we all saw. Then I tried to go fastball in to Mayberry. I didn’t get it in far enough, and he just ambushed it and got it over the wall,’’ Carson said. “It comes with the territory. It’s how you bounce back from it.’’
The bullpen’s ERA swelled to 5.28, the worst in baseball. But truth be told, there’s plenty of blame to go around. The lineup came in averaging 5.2 runs — third-best in the majors — but the Mets have mustered just 2.8 per game and batted just .171 with men in scoring position as they lost four of their last six.
That surely is a big part of manager Terry Collins’ decision to pinch-hit Justin Turner for Marcum in the fourth inning. Marcum had thrown just 71 pitches — well under the 95 limit the club had put him on — but there were men on the corners and two outs with the Mets down just 3-2. Turner got caught looking at strike three by rookie Jonathan Pettibone (1-0).
“They don’t need to hear it every day,” Collins said. “They know. They’re very aware of what the situation is. [Today] we’ve got [Jon Niese] going. It should be a good game. We’ve just got to rise up, as we’ve done so far. So we’ve got to do it again.’’
brian.lewis@nypost.com