NEW YORK -- Johan Santana returned to the Mets' clubhouse on Tuesday with his sprained right ankle nearly recovered and his rehabilitation outing in the rearview mirror.

"I feel good. I was able to recover and do all my things," Santana said. "I'm definitely happy to be back and be around these guys again. I'm getting ready for my next outing."

That outing will come at Citi Field on Saturday against Atlanta, but not before he throws his bullpen session on Wednesday and diagrams a plan for the start with pitching coach Dan Warthen. Santana wasn't sure if he'd get the green light to throw without limitations in the start on Saturday -- his first since he was placed on the DL on July 21 -- but he speculated much of that decision hinged on the session.

The left-handed starter had a strong rehab start at Class A Brooklyn on Sunday, when he threw three scoreless innings and fanned three batters before increasing his pitch count to 90 by throwing three simulated innings in the bullpen.

"It was all about feeling good and feeling 100 percent from top to bottom," Santana said. "I was able to give my ankle some rest in rehab, but at the same time my whole body rest."

With oft-used Byrdak out, Mets call up lefty

NEW YORK -- Prior to tearing the anterior capsule in his left shoulder, Tim Byrdak appeared in a team-high 56 games for the Mets in 2012. The likely season-ending injury was a sign of one thing to manager Terry Collins -- overuse.

"He was in that role that he was where he's had to go out there a lot," Collins said. "There's no question we probably used him more than maybe we should have, but we also wouldn't be here without him."

Left-hander Garrett Olson joined the Mets from Triple-A Buffalo on Tuesday afternoon. Reliever Elvin Ramirez was optioned to Buffalo, and Dillon Gee -- who underwent surgery to replace a portion of a damaged artery in his right shoulder on July 13 -- was placed on the 60-day disabled list to clear a spot for Olson on the Mets' 40-man roster.

"You head into the Atlanta series [on Friday] with all of those left-handed hitters they have, you better have some help for Josh," Collins said. "That's why he's here."

Before the arrival of fellow left-hander Josh Edgin in early July, Byrdak was the only southpaw in the Mets' bullpen, and as a result his workload as a specialist increased. Edgin has provided a viable second left-handed option out of the 'pen -- he hasn't surrendered a run in nine consecutive appearances -- but Byrdak's spiked workload took its toll.

"Injuries are caused by overuse," Collins said. "I've had too many doctors say, 'When they break, they're going to break.' There's not much you can really do about it.

"He's done nothing in the last two years except take the baseball and gotten big outs for us. I just hope he comes out of it OK and can resume pitching."

Collins admitted that even in Spring Training he was searching for a second left-hander to add to his bullpen, but stressed that a viable, effective option was simply unavailable.

"It's one thing to have two left-handers in the bullpen, but if that other second lefty down there can't get left-handed hitters out, he doesn't do you any good," Collins said."

"To me, it's about good stuff in the bullpen. That's what gets people out, whether your left- or right-handed. Tim was that guy, our choice, and we had to ride it."

Olson served as both a starter and reliever for Buffalo, his most recent outing coming on Thursday as a starter. He delivered seven innings of one-run ball against Syracuse, scattering just two hits and striking out seven.

Ideally, Collins said that Edgin will serve primarily as a left-handed specialist, while Olson, who logged nearly 109 innings with Buffalo this season, will face more hitters at a time.

Mets could start platooning Bay, lefties in left

NEW YORK -- Change could be coming in left field as soon as Wednesday, when manager Terry Collins will likely sit Jason Bay in favor of a left-handed hitter.

Collins has become accustomed to platooning his outfielders with the number of injuries the Mets have had to deal with this season, but he's also been adamant about giving Bay the proper amount of time to regain his form as a starting left fielder.

But while Collins has vouched for him, Bay hasn't helped his own cause. In 18 games since returning from the disabled list on July 17, he's hitting .109 with a home run and five RBIs. And on the Mets' 10-game road trip, he went 2-for-31 at the plate as the team's starting left fielder.

"Certainly Jason and I are going to sit down and have a conversation about how we're going to proceed forward," Collins said.

Said Bay: "If I had a better leg to stand on, I could say something. But as of right now, I don't. I don't want to be a distraction. I want to go out there and help out any way that I can."

Left-handed hitters Mike Baxter and Jordany Valdespin have both seen time in left field this season and had their fair share of success at the plate. Valdespin is hitting .260 this season, but holds a .297 batting average and has hit five home runs with 13 RBIs since getting recalled from Triple-A Buffalo on July 5.

Baxter has been quite the success story in his own right. He held a .323 batting average before injuring his left shoulder when he crashed into the left-field wall during Johan Santana's no-hitter on June 1. Since returning from the DL on July 30, he's raised his OBP to .422 with the help of his five-walk game on Monday.

"We're going to make some -- certainly depending on who is on the mound -- some adjustments out there," Collins said. "We've got to get our left-handed bats in the lineup. Those guys have given us good opportunities to win some games, and they're having some pretty good years."

Collins knows he needs to find at-bats for the left-handed-hitting outfielders who are producing, but he also doesn't want to write off Bay. The 30-year-old right-handed hitter started in left on Tuesday against Marlins left-handed starter Wade LeBlanc, and he should still see time in the lineup against left-handers in the future.

"Right now, Jason Bay, he's going to play tonight," Collins said. "Tomorrow's guy [Nathan Eovaldi] has been pretty tough on righties with his breaking stuff. I looked and this weekend we've got a couple lefties, so Jason is going to get a lot of at-bats to get it going."

Worth noting

• Backup catcher Rob Johnson was available on Tuesday if the Mets needed to replace starter Josh Thole. Johnson has been cleared to catch and throw, but he has run into trouble swinging the bat because of his right hand bruise.

• Ruben Tejada extended his career-best hitting streak to 11 games on Sunday, when he recorded two hits in San Diego. With the Marlins coming into town on Tuesday, Collins had nothing but praise for Tejada, offering acknowledgment that the young shortstop's play this season has helped the team move past the departure of Jose Reyes to Miami.

• Ronny Cedeno has one RBI in six of his last seven starts, and 10 RBIs in his last four games. He started at second base on Tuesday, and Daniel Murphy -- hitting .429 since the start of the month -- slid over from his usual spot to play first.