Park was not involved in the decision, as the Mets fell to the Red Sox, 9-5.
Laboring through a 30-pitch first inning, the right-hander walked leadoff hitter Julio Lugo, then struck out Kevin Youkilis looking. David Ortiz's single moved Lugo to third, and a walk to Manny Ramirez loaded the bases.
Park nearly worked out of the jam. After going to a 3-0 count to No. 5 hitter J.D. Drew, Park ran the count full, then got Drew to hit a liner to shortstop Jose Reyes, who bobbled the ball, but still threw out Ramirez at second. Jose Valentin threw to third baseman David Wright, who tagged out the lumbering Ortiz for the double play, but Lugo crossed the plate before the tag was made.
Park, who settled down after that, allowing just a Youkilis single in the third, was pleased with his outing.
"It was pretty good," he said. "I feel like it's been a long time. I pitched five days ago [in a simulated game]. This is kind of [a] totally different intensity. That was like I was throwing [batting practice] -- a simulation game. Today was a real game facing good hitters. The first inning, I feel like I overpitched and rushed, [because of] all the excitement. And then [I came] back the second inning and third inning -- that's what I feel good about.
"It's the first game. Sometimes you overthrow ... I just wondered what was going on. The ball was moving crazy, especially [the] inside fastball for a lefty. I tried to keep the ball down, but sometimes it was moving like crazy. So after the first inning, the pitching coach, Rick [Peterson], told me [I was] maybe a little overthrowing. So I was trying to go 80, 90 percent after that."
Manager Willie Randolph was pleased with what he saw from Park, who is vying with six other candidates -- right-handers Aaron Sele, Jorge Sosa, Mike Pelfrey, Phillip Humber, Alay Soler, and lefty Jason Vargas -- for the fifth spot in the rotation.
"He was overthrowing the ball a little bit," Randolph said. "No matter how many times you've been out there, it's still a little bit foreign at first. But he had pretty good stuff, and I just thought he was being a little bit too careful.
"He came out in the second inning and was challenging hitters a little more. I try to get him to understand, he knows that you got to trust your stuff. If they put the ball in play, you got your defense behind you. And plus, his stuff's good enough to get some ground balls and make some pitches. It's just the fact that I wasn't really going and looking for anything more than what I saw, getting his work in. And if he did struggle a little bit, just overthrowing the ball a little bit -- I was pleased with what I saw."
With the exception of Alex Cora at second base and catcher Doug Mirabelli, the Sox fielded what is expected to be their Opening Day lineup.
"I've faced them a lot," Park said. "They're such good hitters."
"Spring Training or not, no one wants to go out there and get beat up," Randolph said. "Even though it's Spring Training [and] you want to get your work in, there's still a tendency to sometimes be a little careful when you've got those big boppers up there."
Park was 7-7 with a 4.81 ERA in 21 starts for San Diego in 2006, his season curtailed by abdominal pain and intestinal bleeding. The 33-year-old signed a one-year, $600,000 contract Feb. 9, with performance bonuses based on innings that could push his salary to $2.4 million.
After a healthy offseason, Park said he believes his stamina is back.
"I felt very good this past offseason," he said. "Especially physically, after surgery last year. I worked a lot and tried to get stronger. It's a new team. I'm trying to get a job. I want to show myself I can do it better than I pitched in past years."
Without a work visa, Park could not pitch in games for which admission was charged, missing his first scheduled start Friday, against the Cardinals in Jupiter, and instead throwing 35 pitches in a simulated game.
His next outing is expected to be Monday, against the Nationals in Viera.
On Easley Street: Damion Easley, a defensive substitute at second base in the sixth inning for Valentine, went 1-for-2, a three-run homer in the seventh, which scored David Newhan and David Wright to tie the game.
"He's a good fastball hitter," Randolph said. "If you make a mistake middle-in or out over the plate, he can hurt you like that. We expect him to every once in a while pop one for us. He's not a home-run hitter. We're looking for him to maybe drive runs in -- get things started. [It's] nice to see him catch one and get us back in the ballgame."
Sele struggles: Sele followed Park on the mound, giving up four runs on five hits, with a strikeout, in two innings, giving him a Spring Training ERA of 11.25.
"Well, he got some balls up in the zone and he got hit," Randolph said. "That's the way it's going to be at times for him. He needs to locate his pitches, and when he doesn't, he doesn't get the results that he wants. He was OK, just made some fat pitches that he got hurt on."
Stat of the day, Part 1: The Red Sox have issued more than 150 Spring Training credentials to members of the Japanese media covering pitchers Daisuke Matsuzaka and Hideki Okajima.
State of the day, Part 2: The Mets had nearly as many catchers (six) on Wednesday's travel roster as outfielders (seven). The backstops making the trip included Drew Butera, Ramon Castro, Mike DiFelice, Mike Nickeas, Francisco Pena and Jose A. Reyes.
Back for more: The Mets signed Wil Cordero to a Minor League contract Wednesday. The 35-year-old's last game in the Major Leagues was July 18, 2005, with the Nationals. He did not play at all in 2006. He signed a Minor League deal with the Mets on July 27, 2005, after being released by Washington, and he hit .103 (4-for-31) with two RBIs in eight games in Triple-A. In 14 big-league seasons, from 1992-2005, Cordero hit .273 with 122 home runs and 566 RBIs in 1,247 games with the Expos, Red Sox, White Sox, Indians, Pirates, Marlins and Nationals.
Up next: The Mets return to Port St. Lucie to take on the Orioles on Thursday at 1:10 p.m. ET. Orlando Hernandez gets the start vs. Daniel Cabrera. Hernandez will be followed by Pelfrey, Vargas, Scott Schoeneweis and Joe Smith.
Maureen Mullen is a contributor to MLB.com. The Associated Press contributed to this story. This story was not subject to the approval of Major League Baseball or its clubs.