Pagan, who was acquired in a trade with the Cubs in January, is batting .468 (15-for-32) with eight RBIs in 12 Grapefruit League games.
"He's had a fine spring," said Mets manager Willie Randolph. "That's what you do. You come to Spring Training in great shape. He's been getting after it every day and making a play. That's what it's all about. I tell my guys that all the time: You don't get into the numbers, you just play. So he's making a strong bid to make this club. It's still early, but he's playing well."
With two outs in the third inning, Pagan drove a pitch from Sox knuckleballer Tim Wakefield to left-center field, driving in Olmedo Saenz, who had walked, and Argenis Reyes, who singled.
After Boston had scored three times in the bottom half of the frame, it had two baserunners aboard with two outs, but Pagan snared Jed Lowrie's sinking line drive to left field to end the Sox's rally.
"It was a good game," Pagan said. "Unfortunately we didn't win, but I felt good at the plate. I was seeing the ball good off Wakefield. I guess I did pretty good.
"[This spring has been] very nice. I think I've been doing a pretty good job, and I'm happy with my performance."
With Moises Alou scheduled for hernia surgery that will keep him sidelined until May, Pagan has a good chance to crack the big league roster.
"He's done a good job," said Mets general manager Omar Minaya. "He's really playing well -- both offensively and defensively. And with Moises Alou out we feel comfortable. Right now he hasn't made the team, but if he keeps on playing the way he has, it has helped his cause."
Pagan began 2007 at Triple-A Iowa, earning a promotion to the Cubs on May 10. He hit .264 with four home runs, 21 RBIs and four stolen bases in 71 games while with Chicago last season. He started 32 games in the outfield, 28 in center and four in right.
"I got to see him a couple of years ago, so it's not like he was completely foreign to me," Randolph said. "He's always had the talent, so it's nothing [that] really surprised me. He's consistent right now and playing well. His athleticism is what jumps out at you, because he does a lot of things for you. I wouldn't say I'm surprised. It's been a couple of years since I've seen him, and he's matured a little bit."
Maureen Mullen is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.