NEW YORK -- Though admittedly a little early, Mets manager Terry Collins has begun to consider pitching candidates to join the team as September callups, and Jenrry Mejia and Jeurys Familia -- both with Triple-A Buffalo -- top the list of names.

Mejia has served as a starter and reliever with Buffalo this season, but in five games as a starter boasts a 1.16 ERA. In his most recent start on Monday, the right-hander tossed 4 1/3 scoreless innings and scattered just three hits.

"He threw the ball very, very well the other night," Collins said. "If he continues that through four more starts until September, he's got to certainly be looked at as a candidate, depending on how he feels."

Mejia has a 5.48 ERA in 16 relief appearances for Buffalo, but despite the stark difference in figures, Collins said coming out of the bullpen may be his only option at the Major League level. With Matt Harvey occupying a spot in the rotation -- and top prospect Zack Wheeler potentially set to join him next season -- pitching vacancies on the Mets' roster will likely be in the 'pen in 2013.

"As we've told the people in the Minor Leagues, right now we're looking for that guy who can come up and slam the door, that's in the bullpen," Collins said. "Especially looking at what we're going to have next year, at least at this particular moment, what we're looking at starting pitching next year, there may not be a spot. If he's going to want to be on this team, it might have to be as a reliever."

Collins labeled Mejia as a "max effort" player, and cited that a reason for why he'd be better suited for a relief role. But his numbers as a starter are hard to ignore.

"The thought process for a lot of people was that he's such a max effort guy, there's no way he's going to be able to start he's going to have to pitch out of the bullpen," Collins said. "But so far the most success he's had has been as a starter, so we will certainly take a look."

Collins said that Familia would likely fill a similar role if called up in September -- the right-hander would likely see action out of the 'pen. Familia has had several brilliant starts for Buffalo, but has been unable to string them together. In 24 starts, he has a 4.98 ERA.

As lone lefty in 'pen, Edgin to see lot more work

NEW YORK -- Chipper Jones welcomed Josh Edgin to the Majors on July 13 with a home run in the Mets' reliever's big league debut. On Friday night, Dan Uggla treated the southpaw to a little bit of déjà vu.

Uggla hit a two-run home run over the fence in left-center field at Citi Field on Friday after falling behind in the count, and Mets manager Terry Collins said the shot immediately reminded him of Jones' home run off Edgin less than a month earlier.

"It's all location," Collins said. "You can't fall behind Dan Uggla 3-0 and then try to challenge him with balls in the middle of the plate. You're going to lose that more times than you're going to be successful."

As the sole left-hander in Collins' bullpen -- Garrett Olson was designated for assignment on Saturday to clear a roster spot for Johan Santana's return from the disabled list -- Edgin can no longer be utilized simply as a left-handed specialist. As such, Collins admitted before Friday's series opener that the lefty's workload will increase in the future.

Edgin has shut down left-handed hitters since joining the Mets last month, but has struggled against righties, who were hitting .318 (7-for-22) against him entering Saturday. But despite the numbers, Collins was confident that as Edgin continues to adapt to Major League hitters, those figures will improve. And as the only lefty in the 'pen, they certainly have to.

"Josh Edgin can get right-handed hitters out, he's already done it," Collins said. "He's got a very, very good slider, his changeup is very good. He's had a couple of outing when he's had to face them and his sinker's been good.

"[Uggla's home run] is all part of the learning process that goes along with Josh's development here, but he's going to be fine against right-handed hitters."

Worth noting

• The Mets designated left-hander Garrett Olson for assignment on Saturday to clear the roster spot for Johan Santana's activation from the disabled list.

Olson, who was called up from Triple-A Buffalo on Tuesday, appeared in his only game for the Mets on Wednesday against the Marlins. He holds a 108.00 ERA after surrendering four earned runs and retiring just one batter.