Beltran went 1-for-3 and scored a run while serving as designated hitter against the Boston Red Sox.
Beltran described his knee as "tight," but not in any discomfort, and suggested he was running at about 80 percent.
"I felt good -- anxious a little bit at the plate," Beltran said. "I saw the ball well. In order for me to get ready for the season, I need to see live pitching. Today was the first step of seeing live pitching. I just hope to continue to do a little bit more and more every day."
Manager Terry Collins considered using Beltran at DH again on Monday, but Beltran arrived at camp describing himself as "sore in a good way" and preferred to wait another day to DH again.
After talking earlier, Collins later found Beltran in the trainer's room.
"He just said, 'Hey look, I felt great yesterday. I want to work on some things in the cage, is it all right I don't DH today,'" Collins said after the Mets lost 2-1 to the Tigers. "I said absolutely."
"I said, 'Go do your stuff and we'll see how you feel the following day and we'll get you back in there,'" Collins said.
The expectation is Beltran will be in right field in a Grapefruit League game in seven to 10 days.
Collins wasn't worried about Beltran's status Monday.
"I'm just so happy with what went on yesterday," he said.
Facing right-hander Michael Bowden in the second inning Sunday, Beltran took a pair of pitches, then lined a 1-1 single to right field. He eventually scored comfortably from second base on Daniel Murphy's single, also to right field, and slid into the plate.
"We had two outs, a base hit to right field, so my job is to try to score on that play," Beltran said. "Once I'm playing games, I'm not thinking about trying to be cautious. I'm just trying to play the game the way it is. That particular play I needed to score."
The switch-hitting Beltran got a chance the following inning to hit from the right side of the plate. Against left-hander Andrew Miller, Beltran again took two pitches, then flied out to right field.
Against left-hander Hideki Okajima in the fifth, Beltran popped out to right field.
Beltran was thankful to face a pair of southpaws.
"It was good," Beltran said. "Normally you don't see lefties in spring training. ... From the left side I felt like I was a little bit more patient. From the right side I was jumping a little bit. Now I have an idea what I need to work on from the right side."
Beltran halted last season with a week remaining because of pain in his chronically troubled right knee. He recently has indicated the knee feels fine, but there is concern the pounding of a season will again cause the discomfort to flare up. To reduce that chance, Beltran agreed last week to man right field this season, with Angel Pagan handling center field.
However, Beltran -- who will complete a seven-year, $119 million contract this season -- said he is not resigned to playing right field for the remainder of his career.
"Right now I feel like I can get to the balls," Beltran said, comparing his mobility now to pre-January 2010 knee surgery. "I need to spend more time in the outfield. If my knee holds well, I have no doubt what I can do defensively. Catching every ball, that's impossible. Doing the job defensively like I know I have done in the past, I believe I can do that."