"They're guys who have been through everything," manager Larry Bowa said, referring to Wendell and Cook. "They've been to the World Series, played in New York, and they both like to have the ball. They're gamers."
Wendell, a 34-year-old righthander known for his flakiness, is 4-3 with a 3.51 ERA this year. Cook, a 38-year-old lefthander who has been a Phillie before, is 1-1 with a 4.25 ERA.
Chen, 24, began the year in the Phils' rotation, where he was 4-5 with a 5.00 ERA in 16 starts. The lefthander has been at triple-A Scranton/Wilkes-Barre since July 12, going 1-0 with a 3.86 ERA for the Red Barons.
Walker, 25, has spent the entire season at double-A Reading, where he was 7-4 with a 1.88 ERA in 15 games, including 14 starts.
The Mets didn't agree to make the deal until Walker was deemed healthy. He came off the disabled list last night - he has been bothered by elbow problems - and pitched three hitless relief innings.
"After tonight, we're convinced it was nothing serious," Mets general manager Steve Phillips said.
Walker was sent to the Mets' double-A team in Binghamton, while Chen will join the club for today's game against the Phils at Shea Stadium.
To make room for Wendell, Cook and Crespo, the Phils designated outfielder Turner Ward for assignment, and lefthander Ed Vosberg was sent outright to Scranton.
Crespo, 28, a switch-hitter, was batting .197 in 40 games with the Giants. He was hitting .316 as a pinch-hitter (6 for 19) with two homers. This year, he played 16 games at first base, two at second base, and one in right field.
Bowa said Crespo, in addition to being used as a pinch-hitter, might see some action in left field. Crespo is a .252 career hitter (102 for 404).
Wade said the Phils "had an opportunity to move Chen to a number of teams, but we felt being able to get multiple [relievers] sets us up for the remainder of the season ... and hopefully beyond."
Cook, who makes $2.2 million this year, can become a free agent after the season.
Wendell, who is in the first year of a three-year, $9.4 million contract, can opt to be traded after the season because he is in the middle of a multiyear pact.
Wade said that by making the two deals, "we did what we wanted to do - we wanted to add experience in the bullpen and add a lefthanded bat off the bench."
Wade said he would listen to other trade offers before Tuesday's deadline, "but we've met our objectives as far as what we wanted to do."
Said Cook: "It's good to know there are other organizations that think you can still help. I'm excited. The Phillies are right in the thick of it.
"We're trying to be the missing part of the puzzle, and hopefully we can make a run."
"Dennis can pitch every day and I can pitch every day," Wendell said, "so this will help get to [Jose] Mesa."
Sam Carchidi's e-mail address is firstname.lastname@example.org.