SAN DIEGO -- Right-hander Chris Jakubauskas, sidelined first with a concussion and then with a groin strain, has resumed his Minor League rehab assignment. Jakubauskas has joined Triple-A Indianapolis, where he will begin building his arm back to full strength.

Jakubauskas took a line drive to the head on April 24, costing the right-hander nearly two months. He returned to the mound in mid-June only to have his rehab assignment shut down at the beginning of July due to a right groin strain.

After a month of rest, Jakubauskas is back to try and salvage something from the 2010 season, though it's unlikely he'll see any time in Pittsburgh this year. Given how abruptly Jakubauskas' last rehab assignment ended, the Pirates plan to take this stint day-by-day, rather than set particular benchmarks.

"It's been a really tough year since that [concussion] happened," said manager John Russell. "Hopefully he gets healthy. That's the main thing."

Alvarez in rare company with RBI streak

SAN DIEGO -- Pedro Alvarez joined some rare Pirates company with an RBI streak that reached seven games on a bases-loaded walk in Wednesday's 8-5 loss to San Diego.

Not since Frank Colman in 1944 had a Pittsburgh rookie driven in a run in seven consecutive games. Colman's streak of games with an RBI reached eight straight contests that season, ironically enough from Aug. 6-14.

Alvarez's stretch began on Aug. 4 but came to an end in the Pirates' 3-0 loss to the Padres on Thursday.

Alvarez is also the first Pirates player of any experience level to collect an RBI in that many consecutive games since Jason Bay did so in seven straight games in 2005. In fact, no Major League rookie has had an RBI streak of longer than seven games since that '05 season, which featured Dan Johnson's nine-game RBI streak with Oakland.

"I'm just giving myself a chance," Alvarez said.

Pittsburgh has scored 30 runs since this streak began, and Alvarez is responsible for pushing across 11 of them.

Tabata impressing in short time in bigs

SAN DIEGO -- Outfielder Jose Tabata celebrated his 22nd birthday on Thursday by making the 54th start of his still-budding Major League career.

And what Tabata has done in such a short time is plenty notable.

Among all Pirates players with less than 385 at-bats before turning 22 years old, Tabata ranks third with 67 hits. Ahead of him lie only Dick Groat, who had 109 hits in 95 games, and Fred Brickell, who recorded 90 hits in 137 games.

"At that age, and what he's doing, that makes him very special," said manager John Russell. "We saw it two years ago in Spring Training with his approach at the plate. We knew that he was very advanced and had a lot of confidence in what he does, and it shows. He doesn't panic during his at-bats. He's able to use the whole field. And he's got speed."

The consistency shown by Tabata in his first two months in the Majors might be the most impressive figure of all. The outfielder has not gone hitless in consecutive games this season and, after Thursday's loss to San Diego, has hit safely in 19 of his past 21 games. Tabata bumped his batting average all the way up to .303 during that span.

Diaz relishes first big league start with Bucs

SAN DIEGO -- Admittedly surprised to see his name on the lineup card, Argenis Diaz earned his first Major League start Thursday in the Pirates' 3-0 loss to the Padres.

Diaz started at short and batted eighth in the order, drawing a walk and collecting one of Pittsburgh's four hits.

"I've been waiting for that," Diaz said. "I'm just going to try and do the same thing I did in Triple-A. It's different because we're in the big leagues, but baseball is the same."

This is Diaz's second stint with the Pirates this season, though his playing time was limited to three pinch-hit and two pinch-running appearances. He collected his first big league hit on Aug. 1.

"He did some good things in Triple-A, and he's been on the bench," said manager John Russell. "I thought today could be a good day to get him started."

Diaz, considered to be one of the organization's best -- if not the top -- defensive infielder in the system, played regularly with Indianapolis. In 80 games, he hit .248 and committed just seven errors, though he short-hopped a throw to first base against the Padres, leading to an unearned run for starter Zach Duke.

Since rejoining the club on July 31, Diaz has continued to get early work at shortstop, third and second base in order to keep him available as a utility infield option. Diaz has also gotten some work in the outfield, in case a late-inning situation would dictate the need to insert him there.

"It's a challenge, because I'm used to playing every day down there," Diaz said. "Here is different. I do everything every day just to keep my legs loose, my arm loose. It has helped me just watching those guys play. You learn when you watch big league guys play."

Worth noting

The Pirates and Padres donned 1978 retro uniforms for Throwback Thursday at PETCO Park in the series finale. For the Pirates, that meant the return of the pillbox hats, black pants with yellow pinstripes and white jerseys with yellow pinstripes. ... The Professional Baseball Athletic Trainers Society has named State College Spikes trainer Mike Zalno the New-York Penn League athletic trainer of the year for the second consecutive season. ... Pirates starter Zach Duke made his 150th career start on Thursday, just four days after fellow lefty Paul Maholm reached the same milestone. The two are the first pair of Pirates teammates to reach that 150-game start plateau in the same season, according to the Elias Sports Bureau.