SAN DIEGO -- Padres pitcher Andrew Cashner, on the disabled list with a strained right lat muscle, made his first Minor League rehabilitation appearance on Tuesday.

Cashner, pitching for Triple-A Tucson, allowed three hits with two strikeouts in two scoreless innings of work in a game in Fresno. He threw 30 pitches, 21 for strikes.

Cashner landed on the disabled list on July 4, one day after suffering the injury after he completed two innings in a start against the D-backs.

Cashner, who began the season as the Padres' eighth-inning specialist before moving into the rotation in June, will gradually build his endurance with Tucson before he's able to rejoin the Padres.

This season, Cashner is 3-3 with a 3.44 ERA in 30 games. In three starts, he had a 2.53 ERA over 10 2/3 innings.

Pitcher Anthony Bass, on the disabled list since June 21 with right shoulder inflammation, will make his first start for Tucson on Wednesday.

Cabrera is thriving in leadoff role

SAN DIEGO -- It wasn't all that long ago when Padres infielder Everth Cabrera approached manager Bud Black with a question pertaining to his spot in the lineup.

"He's mentioned it before, 'How do I go from the bottom of the order to the top?'" Black said Tuesday.

The short answer, Black said, was to produce. To that end, Cabrera has done so in starts Sunday and Monday from the top of the order, going 6-for-10 with one stolen base and two RBIs.

Not surprisingly, Cabrera was back in the leadoff spot Tuesday against the Pirates. Two games surely rate as a small sample, though Black is encouraged and intrigued about Cabrera hitting leadoff.

"It's more about the potential," Black said. "Based on the speed component, Cabbie has the potential to impact the opponent with his basestealing. Having that at the top of the order is advantageous for our club."

These are the first three games this season that Cabrera has hit leadoff. The Padres have also used Will Venable, Cameron Maybin, Alexi Amarista, Chris Denorfia and Logan Forsythe in that spot.

Cabrera, a switch-hitter, has been far more effective hitting left-handed (.290) than right-handed (.190) this season. But Black wasn't about to make any sweeping, definitive statements about Cabrera, who is 25 years old.

"It's a process for Cabbie," Black said. "He's still developing as a player. He's not a finished product by any means."

Entering Tuesday's game, the Padres' leadoff hitters had the 11th-best on-base percentage in the National League at .316 and the 10th best batting average (.253).

Werner excited for first big league action

SAN DIEGO -- The plan was for Padres manager Bud Black to announce after Tuesday's game that rookie Andrew Werner would be added to the roster to make his Major League debut pitching against the Pirates the following day.

The announcement came sooner, though.

"I was going to announce it after the game until I saw his jersey hanging in his locker," Black said before Tuesday's game against the Pirates.

Werner arrived from Triple-A Tucson in time for the Padres' pregame workout at Petco Park. He will become the 14th starting pitcher used by the team this season when he starts Wednesday's series finale against the Pirates.

"I was pretty surprised. I had been throwing the ball decently, but my last start was probably my worst one of the year," Werner said. "I didn't think there was any shot. I'm just really excited to be here."

Werner will be added to the 40-man roster and 25-man active roster on Wednesday. The team will announce a corresponding roster move at that time.

Werner, a 25-year-old left-hander, was 1-2 with a 5.79 ERA in four starts with Tucson. He started the season with Double-A San Antonio, going 4-8 with a 3.23 ERA in 18 starts.

Black said Werner has "a solid fastball in the high 80s, a good changeup. He's a strike thrower and he attacks and doesn't back down."

Wednesday's outing will be the first Black and pitching coach Darren Balsley have seen of Werner, as he spent all of Spring Training in Minor League camp. Werner signed with the Padres as a non-drafted free agent on Nov. 19, 2010.

Werner is replacing Ross Ohlendorf in the starting rotation. Ohlendorf was optioned to Tucson on Saturday.

Short hops

• The Padres announced Tuesday that they have extended their player-development contract with Class A Lake Elsinore through the 2014 season. The Storm, who play in the California League, have been the Padres' top Class A affiliate since 2001 and have finished with a winning record in nine of the previous 11 seasons. Since becoming a Padres affiliate, 46 former Storm players have reached the Major Leagues and made their debut with the Padres.