SAN DIEGO -- The Padres' deep outfield mix got a little bit deeper on Wednesday afternoon.

San Diego claimed lefty-hitting outfielder Nick Martini from Oakland, with the expectation that he will join the club in San Francisco on Thursday. No corresponding move will be announced until then.

In 61 big league games over the past two seasons, Martini owns a .282/.385/.411 slash line with two homers. He played only six games for the A's this season, however, and was designated for assignment earlier this week to clear roster space when Oakland promoted Seth Brown.

"He's an on-base guy who's done a really nice job of that throughout his entire Minor League career," said Padres manager Andy Green. "He had a really good year last year at the big league level, with kind of intermittent playing time there."

It's unclear how the 29-year-old Martini might fit into the Padres' roster plans. With Josh Naylor, Wil Myers, Hunter Renfroe and Manuel Margot, the Padres have used a regular four-man rotation since Franmil Reyes was traded to Cleveland last month.

The club has a few other lefty-hitting outfield options that aren't on the active roster. The Padres are still optimistic that Franchy Cordero (quad) can return by the end of the season. Travis Jankowski is at Triple-A and Taylor Trammell -- the team's No. 2 prospect, per MLB Pipeline, who arrived in the Reyes trade -- should debut at some point next season.

Still, there's an obvious need for big league-ready left-handed bats in San Diego -- especially those with a penchant for reaching base.

Martini, who has posted a .401 OBP in parts of five seasons at Triple-A, might provide just that. It also helps that Martini will have an option year remaining in 2020 and will be eligible to be shuttled between the Minors and Majors, if necessary.

"The more guys that can put balls in play, get on base, be tough at-bats, the tougher our offense will be," Green said.

When a player's contract is designated for assignment -- often abbreviated "DFA" -- that player is immediately removed from his club's 40-man roster, and 25-man roster if he was on that as well. Within seven days of the transaction (it was previously 10 days), the player must either be traded, released or placed on irrevocable outright waivers.

Margevicius recalled

Left-hander Nick Margevicius was recalled before Wednesday's series finale against the Dodgers, in which the Padres opted for a bullpen day. Margevicius posted a 6.41 ERA in 12 starts this season. This time, he's going to work out of the bullpen.

Margevicius was a surprise addition to the Opening Day rotation. He was solid in April, but was demoted in mid-June after a dreadful six-game stretch in which he recorded a 10.72 ERA. In 12 starts for Double-A Amarillo, Margevicius posted a 4.30 ERA.

"He's worked hard on the fastball command," Green said. "Velo's been up just a touch and the slider, at times, has been sharper."

The Padres optioned lefty-hitting catcher Austin Allen to Triple-A El Paso to clear space. Allen will almost certainly return to the big league club as a September callup. He's a valuable left-handed pinch-hitting option.

AFL rosters revealed

Luis Campusano burst onto the scene with a .325/.396/.512 slash line and a strong defensive showing behind the plate for Class A Advanced Lake Elsinore this season. Now, the Padres No. 8 prospect will get a chance to put his talents on display in the Arizona Fall League.

Rosters were announced for the Fall League on Wednesday afternoon, with the Padres sending a trio of exciting young hitters to play for the Peoria Javelinas. Campusano will be joined by No. 11 prospect Owen Miller and No. 12 prospect Hudson Potts. The club will also send four pitchers to the competition, but those names will be announced at a later date.

The Fall League season begins earlier than it had in previous seasons, with the first games scheduled for Sept. 18. The league consists of six teams made up of prospects from around the league. Nearly 3,000 former Fall Leaguers have advanced to the big leagues.

Campusano has emerged as one of the most exciting young catchers in Minor League Baseball this season. Miller and Potts, meanwhile, are two of the club's most promising infield prospects.

The 22-year-old Miller is batting .285/.350/.421 for Double-A Amarillo and is considered one of the most polished hitters in the Padres' system. Potts' numbers for Amarillo weren't so gaudy (.221/.289/.393), but as a 20-year-old in the Texas League, the Padres feel as though he began to hold his own as the season progressed.