Murphy, who had to be helped off the field in the seventh inning Sunday, landed on the DL with a sprain of the medial collateral ligament in his left knee and almost certainly will not return this season -- prompting the Mets to consider yet another future position switch for him.
Reyes, who left the game five innings earlier, was diagnosed with a mild left hamstring strain that could have serious implications on his free agent value.
For the Mets, the immediate impact was nothing so permanent -- just a bit of roster chaos and a discouraging outlook. The team recalled shortstop Ruben Tejada and outfielder Mike Baxter from Triple-A Buffalo to assume the roster spots of Reyes and Murphy.
"There's no formula that you can come up with," manager Terry Collins said in his attempt at explanation. "These are pretty serious injuries, all of them."
Missing three weeks earlier this season with a strain of the same hamstring, Reyes felt another tweak running to first base in the second inning Sunday. Though an MRI taken later that evening revealed that this tear occurred on a different part of the muscle, Mets general manager Sandy Alderson said that the injuries are not necessarily unrelated.
"The preparation that I have is very good," Reyes said. "I'm a guy that stretches a lot. I do a lot of exercises for my leg to try to get it ready. This is something that just happened, so we need to find a way to keep me on the field. I need to find a way to stay healthy."
In the short term, the Mets will proceed with Tejada at shortstop, knowing Reyes should return by the end of the month. But even Collins acknowledged Monday that given his shortstop's impending free agency, the Mets may be looking at a sneak preview of their infield in 2012.
"We have to be realistic and approach it that way," Collins said, "to say, 'Hey, this is the guy that we think can play every day for us in the future.'"
Reyes and his agent, Peter Greenberg, both said Monday that it is too early to define how a second disabled list stint will affect Reyes' value on the free-agent market. Arguably the game's most productive offensive player over the first three months of this season, Reyes has since shown glimpses of the injury susceptibility that forced him to miss significant portions of the last two seasons.
Those injuries could potentially diminish Reyes' value to the point that the Mets could more realistically re-sign him. Or, if Reyes returns soon and continues posting MVP-caliber numbers, they could have no effect at all.
Prior to his injury, Reyes was leading the National League with a .336 average, 16 triples and 80 runs scored, also ranking second with 34 stolen bases.
"That can happen to anybody -- you're running and you pull a hamstring," Reyes said. "That's part of the game, so I don't worry about what people think. The only thing I worry about is trying to get healthy again and trying to finish the season strong."
While quite possible for Reyes, a quick recovery is not an option for Murphy, who will almost certainly miss the rest of this season despite not needing surgery. This marks the second significant knee injury in 14 months for Murphy, who tore his right MCL while playing second base for Buffalo last June.
The Mets pegged Murphy's timetable for recovery at six to eight weeks, and Murphy expressed confidence given his full recovery from a similar injury last year.
Covering second base on Braves outfielder Jose Constanza's stolen base attempt Sunday, Murphy felt a pop when Constanza's right spike shot up and hit him in the knee. Though Alderson said that Murphy did nothing fundamentally wrong on the play, Collins indicated that Murphy, a natural third baseman, had his leg in an exposed position and might not otherwise have been injured.
"In the back of my mind, I was hoping I was just being a little baby about it and maybe it wasn't that bad," Murphy said. "But I kind of knew."
"I've played a lot of second base and never was in that position," Collins said. "He's got to understand where he needs to be, where his feet need to be. It all comes with the more reps you get out there. Unfortunately, due to what's happened this year, Dan never got them."
Regardless of the source of injury, the Mets must now proceed without Murphy, who ranks fifth in the NL with a .320 average and second since May 21 with a .360 mark. Because of that production, the Mets have guaranteed Murphy -- assuming a full recovery -- a chance to compete again for everyday playing time next spring.
"Any time you're fourth or fifth in the league in hitting, you need to try and find a place for that player to play," Alderson said. "He got to that level, and that's how we view it."
But that competition may come at a more low-risk position. Though Murphy struggled defensively during his forays into the outfield in 2008 and 2009 -- and though Alderson hinted that his offensive profile may not play as strongly at a corner outfield position -- some within the organization believe an outfield assignment could help Murphy stay healthy.
"It depends on what our needs are," Alderson said. "That's the great value in a player like Murphy. He does have versatility. He isn't given the opportunity to master any of those positions, but he plays on both sides of the ball very well in almost all of them. That's the temptation."
That is all a discussion for another day. The immediate recovery for the Mets began Monday at Citi Field, with Baxter on the bench against his former team. A Queens native who played his high school ball at Archbishop Molloy, Baxter was batting .256 with one home run in 11 games for Buffalo, after the Mets claimed him off waivers from the Padres. Tejada, who spent two months with the Mets earlier this season, was hitting .193 in 15 games since his demotion.
For the Mets, the hope is that the team can continue to rebound from injuries despite a dwindling cache of Major League players.
"I really feel particularly bad for Murphy, because he's worked very hard to get back to where he was," Alderson said. "He really personified the way this team has played the first two-thirds of the season. And so I hope the rest of our players keep that in mind as we continue the season without him."