MLB

Harvey gives up lead as Mets fall to Diamondbacks

Don’t pencil in Matt Harvey for that All-Star game start at Citi Field just yet.

The battle for the National League honor likely became a little more interesting Wednesday night, when the Mets ace had his worst performance of the season, stumbling to a 5-3 loss to the Diamondbacks before a sellout crowd of 41,257 on Fireworks Night in the Citi.

Harvey walked off the mound without having recorded an out in the seventh inning, after Eric Chavez swatted the right-hander’s 109th pitch of the night off the left-field fence for an RBI double. Harvey was charged for another run later in the inning, completing his final line: A season’s-worst five earned runs allowed on nine hits and three walks with nine strikeouts over six-plus innings.

Both Harvey and manager Terry Collins cited a rain delay of 1 hour, 51 minutes before the game as a factor that didn’t help the fireballer.

“I had prepared for 7 o’clock, but I’m not one to make an excuse,” Harvey said. “I should have been more prepared and obviously didn’t do a good job of that.”

Collins said Harvey was outside the door of his office at 6:30 p.m. champing at the bit wondering if the game would start as scheduled.

“We know he gets all ramped up to pitch,” Collins said. “But it was all about command tonight. He didn’t have command of his stuff — a lot of deep counts. We’ve seen him pitch a lot better, that’s for sure.”

Harvey (7-2) was considered the NL front-runner to start the All-Star game heading into Wednesday night. But his latest performance raised his ERA to 2.27 — fifth in the league — and probably kept the door ajar for competition such as the Dodgers’ Clayton Kershaw, the Cardinals’ Adam Wainwright and the Diamondbacks’ Patrick Corbin. Rosters for the game will be announced on Saturday, but the starting pitcher usually isn’t named until the following week.

“The All-Star game is not in my mind,” Harvey said. “I had one thing to do, and that’s put up zeroes and I didn’t do that tonight.”

Harvey is scheduled to pitch on Monday in San Francisco — with NL manager Bruce Bochy in the opposing dugout — and then the final game before the All-Star break, on July 14 in Pittsburgh. But the Pittsburgh start almost certainly will be moved up a day if Bochy wants Harvey as his starter in the Midsummer Classic.

“[Harvey] is pretty jacked up about all that he’s facing right now,” Collins said. “He’s all fired up about the All-Star thing, the situation, and next week he’s going to pitch against the Giants and it’s going to be in front of Bruce, so I’m sure he’s going to be all fired up.”

Cody Ross began the unraveling of Harvey’s night with a three-run homer in the sixth inning that gave the Diamondbacks a 3-2 lead. Harvey hung a slider to Ross, who hit a towering fly to left that kept going. Miguel Montero had walked with one out to begin the rally before Martin Prado singled. Jason Kubel whiffed for the second out before Ross became the sixth player to homer against Harvey this season.

Josh Satin’s first major league homer — a solo shot in the fourth on a 92-mph fastball from Randall Delgado — gave the Mets a 2-0 lead. The blast extended Satin’s streak of games reaching base to 14 consecutive games and gave him a nine-game hitting streak.

David Wright slugged a full-count curveball into the left field seats with one out in the fourth to give the Mets a 1-0 lead. The homer was Wright’s 13th of the season, moving him into a tie with John Buck for the team lead. Daniel Murphy homered in the eighth for the Mets’ final run.

Harvey was tested in the first inning, loading the bases with one out on a walk to Montero, but got Prado to hit into a double play. Harvey then struck out the side in the second and two more batters in the third. In the fourth, Omar Quintanilla made a diving stop on Ross’ grounder and flipped to second for the force play to end the inning.

mpuma@nypost.com