"Inexcusable," Murphy said. "It can't happen. Johan threw the ball really well and deserved a lot better than that. I'm better than that. It won't happen like that again."
What happened was a most surprising turn of events. With two outs in the second inning and a man on first base, Santana induced Cody Ross into hitting a routine fly ball to left. Anticipating the end of the inning, he began walking off the mound.
But Murphy, new to left field, watched the ball strike the middle of his raised glove and fall to the field. The runner at first base, Jeremy Hermida, scored. Santana lowered his head. And the inning continued.
"I was lazy to the ball and I got exposed for it," Murphy said. "I didn't get back."
With new life, the Marlins scored again when the next batter, Ronny Paulino poked a single into left field, upping the margin to two. And the Mets, feeble against Johnson, could not recover.
"Here, you have a young man who works extremely hard and he's getting better," manager Jerry Manuel said of Murphy. "He's getting better. I don't think you're going to see that type of stuff from him on a regular basis. I really don't. I think that's just something that out of nowhere happened."
The whole situation was akin to the early portion of last season, when the Mets did not regularly provide offensive support for Santana and watched the bullpen blow leads on seven occasions when they did. This version of Santana was every bit as good as that one, striking out 13 Marlins and inspiring the notion that if not for Murphy's misplay, the game may have remained scoreless deep into Sunday afternoon.
Manuel said he even considered Santana's performance every bit as impressive as the one his ace offered on the penultimate day of last season, when he fired a three-hitter with a torn meniscus in his left knee.
But for everything Santana was, he was not as effective as Johnson, who -- less than two years removed from Tommy John surgery -- took a no-hitter into the sixth inning. With what David Wright called an "elite" fastball in his arsenal, Johnson struck out seven, allowing five hits. Not until the ninth inning did the Mets muster anything resembling a rally, but Johnson, with the tying run on base, retired Ryan Church on a fly ball to cap his complete game -- just the Marlins' third since Sept. 16, 2006.
"There's not much you can do offensively when he's throwing the ball like that," Wright said. "We finally got to him a little bit there late, but it was a little too late."
For the Mets, playing Murphy in left field is a sacrifice they're willing to make in order to have his bat be a fixture in the lineup. A natural infielder, Murphy only began playing the outfield regularly as a rookie last summer. And though he has had some adventures, his defensive struggles have never before become the focal point of a game.
Had anyone but Santana been pitching for the Mets, Murphy may have even received something of a pass. But Santana's brilliance, matching Johnson pitch for pitch, made it clear that the Mets lost this game for one reason more than any other.
Earlier in the week, Manuel nixed the idea of having offensive-minded outfielder Gary Sheffield join Sunday's starting lineup in an effort to put his best defensive team on the field. Anticipating that runs would be at a premium, Manuel opted to focus on defense.
And it turns out Manuel's premonitions were correct -- though he was looking toward the wrong corner of the diamond.
"It could have happened to anybody," Manuel said. "Because of the fact that he's transitioning from one defensive position to another, we tend to put extra emphasis or concern on that, but I refuse to be concerned with that at this point."
What he is concerned with is a defensive carelessness that has seemed to plague most of his team throughout the first week of the season. Murphy's error was, in his own words, inexcusable. And it has not been the only one.
Such lapses, Manuel knows, could mean the difference between playing baseball in October and playing golf. And so when the Mets return to their new home, Citi Field, Monday afternoon, they will immediately go to work.
"We're going to take infield, we're going to take outfield, we're going to take infield again," Manuel said, only half-joking. "We're going to do infield early, we're going to do infield late. We're going to do some things."