That group includes outfield prospect Matt den Dekker, whom the Mets recalled Tuesday to replace Byrd on the roster, along with backup catcher Anthony Recker and left-handed reliever Robert Carson, who took Harvey's roster spot after he was officially placed on the disabled list. But the arrival of those three did not prevent other Mets from lamenting the teammates they had lost.
Byrd, who turns 36 on Friday, batted .285 with a career-high 21 home runs in 117 games for the Mets, after signing as a Minor League free agent last winter. While he has enjoyed an all-around great season, including seven outfield assists and positive range values on defense, his most superlative asset was his ability to crush left-handed pitching.
Since May 27, Byrd ranks second in baseball behind teammate David Wright with a .420 batting average against lefties, and places third behind Miguel Cabrera, Wright and Jayson Werth with a 1.147 OPS.
That sort of production, along with Byrd's low salary, created a market for him prior to the July 31 non-waiver Trade Deadline. But the Mets ultimately kept Byrd, citing both a desire to win as many games as possible down the stretch and a lack of suitable offers.
On Monday, the Mets' ability to win took a significant hit when Harvey learned he has a partially torn ulnar collateral ligament in his right elbow, which may sideline him until 2015. One day later, a suitable offer for Byrd apparently arrived, though general manager Sandy Alderson stressed that there was no link between the two events.
"This was more coincidental than anything else," Alderson said, noting that if anything, he was wary of stripping the team of its top run producer one day after losing its best pitcher. "To the extent that there was any influence in this situation from the Harvey injury, it would have been not to do the deal. But we felt that this was in our best interest."
Buck, 33, batted .215 with 15 home runs and 60 RBIs in 101 games for the Mets, though 10 of the homers and 29 of the RBIs came from Opening Day through May 3. Since that time, he has hit .198 with five home runs, a .282 on-base percentage and a .282 slugging mark -- numbers that the Mets could stomach thanks to his mentoring of top catching prospect Travis d'Arnaud.
"He was always there for me and he will continue to always be there for me," d'Arnaud said. "I'm sure if he was here, I would have had tons of more questions. I've been here for a week and I've had hundreds of questions already."
When Buck went on paternity leave earlier this month, the Mets recalled d'Arnaud for a three-game trial to replace him. Satisfied by what they saw, they kept d'Arnaud around even after Buck returned, naming the rookie their new starting catcher.
"I back my front office completely because they don't do things on a whim," Collins said. "There's a plan. And if they feel that this is the best move for this organization going forward, that this kid that we got is going to help us down the road, then it's the move we had to make."
Herrera, 19, was batting .265 with a .751 OPS in 109 games for Pittsburgh's Class A West Virginia affiliate. The Pirates' 11th-ranked player on MLB.com's 2013 Prospect Watch, Herrera had 11 home runs, 11 steals and 110 strikeouts while playing exclusively at second base. He has also appeared at third base in the past.
"He's got some power," Alderson said of Herrera, who will report to Class A Savannah. "He runs pretty well. He's probably a second baseman. He's an exciting talent, multidimensional in a sense, and we'll see where it goes."
But Herrera, like Byrd and Buck, will not be able to help the Mets down the stretch. That puts Collins in an interesting spot, attempting to squeeze production out of a roster missing its best pitcher in Harvey, three other starters in Jenrry Mejia, Jeremy Hefner and Johan Santana, two closers in Bobby Parnell and Frank Francisco, and three of its top four RBI leaders in Byrd, Buck and Wright.
Though Collins is entering the final weeks of his expiring contract, Alderson indicated that the manager will not lose his job over a poor month of September.
"How Terry is evaluated is beyond simply wins and losses," Alderson said. "To the extent that it's perceived that this will make it more difficult for him to win -- and I don't necessarily hold to that belief -- obviously all the circumstances will be taken into account."