Murphy suffered a Grade 2 strain of the medial collateral ligament in his left knee and will miss the remainder of the season. Reyes suffered a left hamstring strain, the same injury that landed him on the DL in June.
"I think this one is not that bad. I think it's a little bit better," Reyes said, comparing the two injuries. "I'm going to do my treatment and hopefully I'll be on the field as soon as possible."
"They're very aware of the situation," first-year manager Terry Collins said. "We aren't going to feel sorry for ourselves because we've got two big pieces of our puzzle out of the lineup. And yes, it's rhetoric sometimes, but I know they know I believe it. But they're going to hear it again."
Both players ranked in the top five in the National League in batting.
Shortstop Ruben Tejada and outfielder/first baseman Mike Baxter were promoted from Triple-A Buffalo to fill those roster spots. Tejada will handle the shortstop duties, as he has done in the past with Reyes injured.
"It is disappointing, frustrating at the same time, because I don't want to get hurt. I want to be on the field doing what I do -- playing baseball," Reyes said. "It is what it is. It's something that just happened."
Reyes said he felt it running to first base in his lone at-bat.
"I felt something a couple of steps before I got to the base. I felt something was not normal there," Reyes said. "I felt something pull in my leg -- a little bit, nothing crazy -- but I felt something different there. That's why I came out of the game. ... I hit that groundball. I was running fine to first base. Before I got to the base, that's when I felt it."
Murphy said he was relieved that the injury was confined to the MCL in his left knee, and did not affect the ACL or meniscus. He had a similar injury to the MCL in his other knee last season.
"I'm frustrated I'm going to have to miss the rest of the year," Murphy said. "But, considering, it's probably the best news I could have gotten. I know how this story ends. My right knee felt great this year. I know that this injury isn't as severe. So I know I'll be back. It's just frustrating I have to take these two, maybe three months at the most, I feel like, to get healthy."
Murphy did not assign any blame to Atlanta's Jose Constanza, who slid into him.
"It was just an aggressive slide," Murphy said.
Reyes' injury does more than limit his playing time -- it might affect his value on the upcoming free agent market.
Mets owner Fred Wilpon fired a shot in May, saying there is no way Reyes would get Carl Crawford money -- seven years, $142 million -- as a free agent next offseason, but for a while it seemed like he would eat his words, as Reyes began posting MVP-caliber numbers with no hint of the leg injuries that tormented him early in his career.
But two trips to the DL for left hamstring strains later, will Wilpon prove correct?
"I think it will have a minor impact," a front-office executive from another club predicted about Reyes' injuries. "Teams get crazy in free agency. And the tools, upside, positional scarcity still remain. It only takes one team. And it's hard to make the case that Carl Crawford as a left fielder had more upside than Reyes as a shortstop, especially if he wins a batting title."
Former Mets general manager Jim Duquette largely agreed.
"Boy, the way he was playing I thought there would be that team out there," Duquette said about a Crawford-type offer. "I think this does make a team pause on that front. But, then again, I look at what he's capable of and the position and the lack of productivity at shortstop and say, 'Well, somebody might just do it.' I can't rule it out, although it can't help but impact it a little bit."
Reyes, for his part, was unfazed by the impact on looming bidding for his services. Mets GM Sandy Alderson said he would continue to honor Reyes and agent Peter Greenberg's request not to engage in in-season negotiations.
"I don't worry about that," Reyes said. "I don't want to get an injury. Something happens. That can happen to anybody. You run and you pull a hamstring. That's part of the game. I don't worry about what people think. The only thing I worry about is to try to get healthy again and try to finish the season strong."
Baxter underwent surgery earlier this year to repair left thumb ligaments, which he injured during spring training. He made his major league debut last Sept. 6 with San Diego and appeared in nine games, although none as a starter. The waiver claim came on the recommendation of former Padres executive Paul DePodesta, who is now with the Mets.
After four games with Class A St. Lucie following the waiver claim while still rehabbing following the surgery, Baxter has played 11 games with Triple-A Buffalo, hitting .256 with a homer and five RBIs. The lefty-hitting Baxter has played in 147 minor league games at first base.
But he had never been to Citi Field, which opened in 2009, before arriving in the clubhouse Monday.
"So far, for the first hour, it's been fantastic," said Baxter, who couldn't even estimate how many family members and friends might be in the stands Monday night. "I turned my phone off."
Adam Rubin covers the Mets for ESPNNewYork.com. Information from The Associated Press was used in this report.