After Late Clutch Hit, Mets" Bats Fall Silent in Extra Innings Fresh off a plane from Nashville after playing a Class AAA game, outfielder Mike Baxter arrived in the Mets" clubhouse early Saturday morning - an early indication of the severity of David Wright's injury the night before. The confirmation that Wright would be placed on the disabled list with a right hamstring strain came a little later. But Baxter had been around the Mets often enough to recognize the implication. "He's the heart and soul of this team," Baxter said. Wright's offensive production, his presence in the middle of the team's lineup, his slick defensive ability, his leadership and steadiness - the Mets were faced with replacing all of them overnight, as if such remedies could be found at a 24-hour pharmacy. No such contingency plan could be hatched Saturday, and the offense struggled in a 4-3 loss in 12 innings to the Kansas City Royals at Citi Field. The 36-year-old left-hander Bruce Chen, with a not-so-blazing 86-mile-per-hour fastball and a crafty slider, flummoxed the Mets" lineup for six innings, allowing one run and four hits with eight strikeouts. The Mets showed some fight after Chen left the game, tying the score at 3-3 in the eighth on a two-run single by Josh Satin. But in extra innings, the offense again fell silent: 13 of the final 14 batters were retired by Kansas City's relievers. In the 12th, pinch-hitter Justin Maxwell homered down the left-field line off Mets reliever David Aardsma to give the Royals a 4-3 lead. Greg Holland closed down the Mets in the bottom of the inning for his 29th save. After the game, Manager Terry Collins said missing Wright was not an excuse for falling into despair and losing. "There's some guys here that are determined to show people they belong here," Collins said. This is the opportunity they've been waiting for for a long time. They're not going to put their heads down. They're going to continue to battle. But the margin for error for the Mets" pitching staff has been trimmed even thinner. The Mets shuffled their lineup Friday to try to produce more offense, moving Daniel Murphy down to the fifth spot and Ike Davis down to the seventh. That was before they lost Wright, who was second on the team in home runs, third in runs batted in and among the league leaders in hits and on-base percentage. Without him, the offense appeared punchless against Chen, who allowed a solo home run to Murphy in the second inning - the Mets" only extra-base hit of the game. Mets starter Jeremy Hefner pitched well, but he was hurt by a three-run third inning in which he surrendered five hits, including a solo home run by George Kottaras. Alex Gordon and Miguel Tejada drove in the other two runs. After Kottaras's homer, it took Hefner some time to settle down. "That's a pitch he's been hurt on because he doesn't get it down," Collins said. He left it up. But he settled in and got it as far as he could. We just didn't mount much of an offense today. Hefner was supposed to pitch Sunday, but the rotation was thrown off by injuries to relievers Josh Edgin and Bobby Parnell, which left the bullpen thin. As a result, Carlos Torres, Saturday's expected starter, pitched in relief Friday, and the Mets" six-man rotation was curbed back to five. Hefner said he was made aware of the potential change before Friday's game. He lasted six innings and allowed three runs, but his earned run average is 9.68 in four starts since the All-Star break, after he posted a 1.76 E.R.A. in his previous eight outings, the best in the majors over that period. "I'm still not where I want to be," Hefner said. I still made some mistakes that can be corrected. But it is encouraging to throw a quality start up there. Unfortunately, we didn't win. Six Mets pitchers did not walk a batter. It was the first time the team had played at least 12 innings without allowing a walk. ...The rotation was essentially bumped up a day. Zack Wheeler will start Sunday's game. After Monday's off day, Jenrry Mejia will pitch Tuesday, Matt Harvey on Wednesday and Dillon Gee on Thursday against the Rockies.