SAN DIEGO (AP) -- The pain in Jenrry Mejia's arm overshadowed Travis d'Arnaud's debut for the New York Mets.
Mejia left early with discomfort in his surgically repaired elbow, and the San Diego Padres took advantage by piling up 15 hits Saturday night in an 8-2 victory over the Mets.
Mejia exited in the fourth inning after throwing two balls to Logan Forsythe. The right-hander, who had Tommy John surgery in 2011, walked off the mound and was met by manager Terry Collins. Mejia has been pitching with a bone spur in his elbow, and it had been determined that he would undergo offseason surgery.
"We knew that there was a time when it might come back," Collins said.
Called up from the minors last month, the 23-year-old Mejia threw seven shutout innings in his first outing of the season against Washington.
He entered Saturday with a 2.22 ERA in four starts, an encouraging sign for a pitcher once considered a top prospect before injuries slowed his development.
Now, the Mets will have to see how Mejia's rebuilt elbow responds after he was forced from the game.
"It was a matter of pain threshold and it was exceeded apparently (Saturday night), and he had to come out," general manager Sandy Alderson said. "The doctor here took a look at him but at this point it's about his symptoms. Obviously severe and we will see where this takes us."
D'Arnaud, a highly touted prospect acquired from Toronto in the R.A. Dickey trade last offseason, went 0 for 2 with two walks in his first major league game. The Padres stole three bases against him and he allowed a passed ball.
"You could see he was a little nervous," Collins said. "I thought he was fine. At the plate, he looked all right. He hasn't caught a couple of these guys but I thought he did fine."
The young catcher enjoyed his debut.
"It was one of those things everyone dreams they can have," d'Arnaud said. "I can't even describe it. Unfortunately, we got the loss."
D'Arnaud said he had no idea Mejia was hurting.
"I couldn't really tell anything was wrong with him until he threw that pitch and walked off the mound kind of funny," d'Arnaud said.
Will Venable had four hits and San Diego got home runs from Nick Hundley and Jedd Gyorko in snapping a three-game losing streak.
Edinson Volquez (9-10) worked five innings for the win and Venable extended his career-high hitting streak to 14 games, the longest active run in the National League.
"The bats woke up a little bit," Padres manager Bud Black said.
Volquez earned his first career victory against the Mets despite reaching 100 pitches in five innings.
Mejia was replaced by David Aardsma, and moments later the Padres broke a 1-all tie.
Forsythe singled off Aardsma (2-2) and scored on Hundley's two-run homer to left field. It was Hundley's second hit in his first game back after spending two days on the paternity list.
"That's the best moment of my career by far," Hundley said of his career-high 10th homer. "I couldn't stop smiling. I thought about my daughter and got a little emotional on the bench."
The Padres stretched their lead to 4-1 when Alexi Amarista's sharp single scored Venable after he doubled down the right-field line.
The Mets cut it to 4-2 on Wilmer Flores' RBI double in the fifth. The Padres pushed it back to 5-2 on Jesus Guzman's RBI single in the bottom half.
Gyorko added a three-run homer in the eighth.
Venable singled in his first at-bat and stole second. Amarista moved Venable to third with a groundout and, when Yonder Alonso walked, the Padres had runners on the corners.
Mejia retired Gyorko, but Chris Denorfia followed with a run-scoring single.
San Diego's 1-0 lead was in jeopardy in the second, when the Mets loaded the bases with two outs on walks to d'Arnaud and Omar Quintanilla and a single by Juan Lagares.
Mejia hit a chopper near the plate, with Volquez and Hundley converging on it. Volquez fielded the ball near the first base line and threw across his body to nip Mejia at first.
But the Mets tied the game in the third on Daniel Murphy's RBI single, which scored Eric Young Jr. after he reached on a bunt and stole second.
NOTES: New York called up d'Arnaud from Triple-A Las Vegas after starting catcher John Buck went on the paternity list Friday. Both were obtained in the December deal that sent Dickey to the Toronto Blue Jays. ... D'Arnaud will catch All-Star RHP Matt Harvey on Sunday, a tandem the Mets hope is a foundation for the future. "That certainly will be a challenge for him because Matt is a different animal than those other guys," Collins said. "But as I talked to Travis this morning, I said, 'Listen, we've got a game plan. Stay with it. Trust it, and obviously have some input if something isn't working.'" ... Padres LHP Eric Stults (8-10, 3.68 ERA) faces Harvey (9-4, 2.23) in Sunday's series finale.
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