SAN DIEGO -- The Padres' bullpen has been downright stingy of late, but they may be about to get even more formidable this weekend, as veteran arms Joe Thatcher and Huston Street are set to rejoin the team after August stints on the disabled list.

Thatcher, who was battling right knee tendinitis and was placed on the disabled list retroactive to July 26, is pitching a rehab outing Wednesday with Class A Lake Elsinore. If all goes well, manager Bud Black says he expects the 30-year-old lefty specialist to fly with the team to Colorado and be activated in time for the series opener with the Rockies on Friday.

Street, who is a perfect 21-for-21 in save opportunities this year, was placed on the disabled list Aug. 11 with a strained left calf. He will head to Lake Elsinore on Friday for a rehab outing, and if all goes to plan, will fly to Colorado on Saturday in time to be activated for Sunday's game, according to Black.

Street hasn't given up a run since June 17, a 20 1/3-innings scoreless streak. He's struck out 45 batters in 36 innings this season.

Thatcher is 0-4 in 40 appearances this year, but has a 3.42 ERA and has struck out 28 in 26 1/3 innings pitched.

Both restore a veteran presence to a bullpen that currently is home to seven rookies and Luke Gregerson, who has split closing duties with Dale Thayer in Street's absence.

Kelly among prospects heading to AFL

SAN DIEGO -- As Padres' fans well know, there was a highly-anticipated announcement regarding the future of the organization made Wednesday. In addition to the sale of the team, the Padres also finalized which Padres prospects would be heading to the Arizona Fall League.

Eight Padres prospects will be playing in the league's 20th season, including four of the team's top six prospects, according to MLB.com.

Headlining the octet is the organization's No. 1 prospect, Casey Kelly, who made a successful Major League debut Monday night. Outfielder Rymer Liriano (No. 2 Padres' prospect), infielder Cory Spangenberg (No. 5), and left-hander Robbie Erlin (No. 6) will be making the trip with Kelly, as will right-handed pitchers Kevin Quackenbush and Matt Stites. Infielders Nate Freiman and Jeudy Valdez round out the San Diego corps.

The Arizona Fall League is a well-respected destination for many would-be big leaguers, and several current Padres -- including Chase Headley and Cameron Maybin -- played there.

The league consists of six teams that play in six Cactus League stadiums beginning on Oct. 9. The season ends with a championship game on Nov. 17.

For many prospects, like Spangenberg or Liriano, the Fall League experience is a chance to be exposed to a higher level of competition while continuing to polish their skill set.

"For Liriano, it will be a good test for him against a little better competition, little different environment," Padres manager Bud Black said. "Same with Spangenberg, just keep playing, keep getting repetitions."

For those, like Kelly, who seem on the cusp of extended stints at Triple-A or even the big leagues, it's all about getting more innings and more repetitions.

Kelly, in particular, will head to Arizona to build on a 2012 season that saw him miss significant time with a right elbow ligament strain suffered after just two Triple-A starts. He returned in August, and will head to Arizona after September with the Padres in order to build his innings count closer to 100, but not necessarily in order to make a huge jump forward in 2013, unless the organization feels he's gotten enough work in before then.

"I think I'd be going to get more innings, just because I might end up under one hundred innings after this year, and I don't want to be behind heading into next year," Kelly said. "We'll see how the rest of the season goes, and then if I need more innings at the end of the year, then I'll go there to pitch."

Lefty Robbie Erlin also missed three months with elbow issues, only returning in August, and is headed to the AFL for the same reason Kelly is: to try to make up some of those lost innings.

"I think for Casey and Robbie, you're talking about two starting pitchers who, the majority of their season was interrupted, so this gives them a chance to go down and pitch," Black said. "They'll continue to work on the things they need to work on, get arm strength, get their innings up."

Short hops

• Manager Bud Black said he expects Anthony Bass and Andrew Cashner to be recalled as soon as each completes one more rehab start. Cashner is scheduled for that outing Friday, while Bass plans to pitch Sunday. Rosters expand Saturday.

• The Padres saw a handful of members of the organization earn postseason recognition in the California League for their 2012 efforts. Class A Lake Elsinore's Peter Hayes was named "Turf Manager of the Year," while pitchers Matt Andriese and Kevin Quackenbush were both named to the league's postseason all-star squad. The Storm's Tommy Medica was named to the team as a designated hitter for his .338 average and 18 home runs in 89 games this season.

Prospects Austin Hedges and right-handed pitcher Adys Portillo were named to the Midwest League's 2012 postseason all-star team for their work with the Class A Fort Wayne Tin Caps this year. Hedges hit .278 with 10 homers and 51 RBIs in 92 games this year. Portillo was 6-6 with a 1.87 ERA in 18 starts for the Tin Caps this year.

• Catcher Nick Hundley (arthroscopic surgery on his right knee) and infielder James Darnell (arthroscopic surgery on his left shoulder) both underwent successful surgeries Wednesday at Scripps Clinic.