PORT ST. LUCIE, Fla. -- Second baseman Daniel Murphy took 20 to 25 swings in the batting cages again on Saturday, as he works back from a strained right intercostal muscle.

The 27-year-old has been taking soft toss swings, "re-acclimating" his body to baseball movements and building up his strength.

Murphy didn't give a specific date for his Grapefruit League debut, but the team will continue to evaluate how he feels every day. His schedule is as follows: Sunday is a "light day," "ramp it up on Monday" and take Tuesday off.

"I think we decided as an organization to play it really on the safe side," Murphy said. "It's a long spring, it's a long season and something we don't want to crop up again. We really took our time and took days off when we felt days were needed. Once we started the work, we wanted to continue to progress up. So far we've done well. I feel good."

When Murphy does return to the lineup, he will be eased back into action. It could be for a couple at-bats and a few innings in the field. The injury occurred on the first day of camp.

"I'm getting close," Murphy said. "It started the way [the] beginning of spring would, and once I get my legs underneath me I should be OK."

Santana works on stretching on Saturday

PORT ST. LUCIE, Fla. -- In a sea of blue and orange jerseys, Johan Santana's No. 57 was nowhere to be seen as his teammates took part in Saturday morning workouts.

Instead, the 33-year-old left-hander stayed behind to focus on shoulder stretches and extra treatment.

Mets manager Terry Collins said the southpaw's status remains day to day in terms of when he will return to the mound and make his Grapefruit League debut.

"[I] talked to him this morning and asked what he was going to do today," Collins said. "[He] thought he should do some stretching exercises for the flexibility in his shoulder and I told him, 'By all means get it done and make sure you're ready to go.' We would certainly hope something next week, but if it's not, it's not. Part of our conversation was he's ready when he's ready."

A week ago a report stated the Mets were unhappy that the two-time Cy Young Award winner reported to camp not in pitching shape. A day later, Santana threw off a mound, veering off his schedule.

Collins and pitching coach Dan Warthen had him return to his previous pace, which includes his current long toss program. He threw off a back mound at the Mets complex on Wednesday, and also had a light long-toss session. If all goes smoothly, he would progress to bullpen sessions and batting practice.

Warthen said Santana felt great on Monday following his time on the mound. Santana will remain on the long toss program until he tells the coaching staff otherwise.

"When he's ready to go, that's going to be the day he goes," Warthen said. "We don't want to rush anything. We don't want to take any chances of getting a setback. Just waiting for the strength for him to say, 'I need to face hitters. I'm feeling really good right now.' He's going to say it's time. 'I feel great, I want to go out there and face hitters.'"

Byrd happy to help wherever he is needed

PORT ST. LUCIE, Fla. -- Outfielder Marlon Byrd arrived to camp with one focus after signing a Minor League contract with the Mets a month ago: make the team.

So far the 35-year-old has given manager Terry Collins reason to believe he should. Following Saturday's action, he is hitting .400 (8-for-20) with three doubles and three RBIs through eight games.

"I think every year you have to prove yourself -- it doesn't matter who you are," said Byrd, who is trying to make his sixth big league team. "I have to prove I belong on this team. That was my whole goal, and my plan going here."

Collins inserted Byrd into the leadoff spot for the first time this spring during Saturday afternoon's game against the Astros. He started in right field.

In 2012, the 11-year veteran's season prematurely came to an end after just 47 games with the Cubs and Red Sox when he received a 50-game suspension, testing positive for Tamoxifen. Byrd had said it was a result of medication he was taking for a years-old condition that is unrelated to baseball and recurred during the offseason.

With a group of young outfielders that includes Matt den Dekker, Kirk Nieuwenhuis and Cowgill, Byrd offers an experienced presence. He can also play all three outfield positions.

"Whatever they want me to do, I'm here to help this team win," Byrd said. "Wherever I fit in that's the way I want Terry to use me. If I was stuck in one position it would make it a little bit tougher to make this team, but being able to play all three helps."

Worth noting

• Johan Santana, who has yet to pitch in a Grapefruit League game after coaches noticed a lack of arm speed at the beginning of camp, did not participate in the team's Saturday morning workouts.

• Pitching coach Dan Warthen remains optimistic that closer Frank Francisco can pitch on Sunday. The right-hander has been battling inflammation in his right elbow. Earlier in the week Francisco had hoped to pitch on Saturday.

• Top pitching prospect Zack Wheeler is scheduled to pitch a simulated game in Port St. Lucie on Sunday. The right-hander strained his right oblique muscle on Feb. 27. He threw a bullpen session on Thursday.

• Outfielder Kirk Nieuwenhuis, whose bone bruise on his left knee has sidelined him for a week, aims to return to the field on Wednesday. He ran 10 minutes in the pool on Saturday.

• Following his three scoreless innings against the Astros, right-hander Jeremy Hefner threw 25 more pitches to simulate an additional two frames. "I'm throwing a lot of strikes, getting ahead for the most part," Hefner said. "I felt good. Offspeed was working well and three solid innings. ... I was happy with the outing."