SAN DIEGO -- Francisco Mejía's balky left knee has healed, but the Padres' 23-year-old catcher is still probably at least 10 days from his return to the big league club.

After missing three weeks with a left knee sprain, Mejia was activated from the injured list on Saturday. But the club optioned him to Triple-A El Paso -- where he’s spent the past 12 days rehabbing -- to continue getting him regular starts.

In sporadic playing time behind starter Austin Hedges this season, Mejia was hitting just .167 with a .466 OPS before his early-May injury. The switch-hitting backstop has a high-upside bat, but he hasn't put it together in the big leagues yet.

"In Franky's case: Go play baseball consistently, work through some things offensively and defensively," said Padres skipper Andy Green. "He's done some nice things down there. We want him to continue to work on those things. We fully expect to see him here in the near future."

In eight rehab appearances, Mejia was batting .391/.414/.652. The Padres insist they don't put much stock into those numbers, given the nature of the Pacific Coast League -- and El Paso in particular -- as a hitter's paradise.

"We know specifically what we're looking for, and it has very little to do with the slash line right now," Green said. "It has a lot more to do with the way the game's being played, and things we're looking for that are important to us that we'll keep internal. ... The slash line, for us, doesn't matter a ton."

If Mejia continues to rake, however, there might be a place for him to receive more playing time in the big leagues. Hedges has been arguably been the game’s best defensive catcher this season, but he's done very little at the plate.

Right now, it's clear the club still views Hedges as the everyday catcher, prompting Saturday’s decision to option Mejia.

Technically, the Padres didn't need to make that decision for another week. But by optioning him Saturday, they ensured that he'd be eligible to return in 10 days. If there's an injury in that span, however, Mejia could be recalled at any time.

Noteworthy

• For the first time since Josh Naylor's promotion to the big leagues last week, the Padres opted for an outfield alignment with Naylor in left, Wil Myers in center and Franmil Reyes in right. Suffice it to say, they're sacrificing quite a bit defensively with that group.

Hunter Renfroe, the team leader in OPS, received the night off after homering on Friday -- a testament to the team's desire to let the rookie Naylor play against right-handed pitching.

"As long as Josh is here, we're committed to getting him some measure of consistent at-bats," Green said. "We trust his bat, we believe he's going to hit for us, we believe he's going to be a real big league hitter. The only real way to see that is to write his name in the lineup and let him play baseball."

Naylor came through for his manager Saturday night by hitting his first big league home run off Miami starter Jose Urena.

• To clear space on the roster for Saturday starter Nick Margevicius, the Padres optioned right-hander Phil Maton to Triple-A. Maton has allowed runs in three of his last four outings, and he did so without recording an out in the last two.

• Catcher Chris Stewart exercised his opt-out, and he was let go by El Paso on Saturday. The veteran backstop signed a Minors deal in the offseason with an opt-out if he hadn't been rostered by June 1. He was hitting .277/.333/.354 with El Paso, but he didn't figure to have a path to playing time with Hedges, Mejia and Austin Allen in his way.