OAKLAND -- A.J. Griffin will take his rehab work to Triple-A Sacramento on Wednesday, when the A's righty will start for the River Cats as he continues to nurse his strained throwing shoulder back to health.

Griffin is expected to throw 65 pitches and will make at least one other Minor League start before Oakland makes a decision on his readiness for big league action. Normally tough to crack, the A's pitching staff may welcome in the added arm at that time thanks to expanding rosters.

"We'll be in September at that point, so we'll take a look at where we are and what we need as far as added pitching depth," manager Bob Melvin said.

The rookie Griffin was superb for the A's before being sidelined, compiling a 3-0 record and 2.42 ERA in eight starts.

Anderson off the DL, set to make debut Tuesday

OAKLAND -- The rich get richer.

Already booming with talent, Oakland's pitching staff will welcome in more of it via a familiar face on Tuesday, when lefty Brett Anderson is scheduled to make his first big league start in more than a year.

The 24-year-old Anderson, reinstated from the disabled list on Monday following a 13-month rehab from Tommy John surgery, will face the visiting Twins in his season debut. He takes the rotation spot of righty Dan Straily, who was optioned to Triple-A Sacramento as the corresponding move despite an impressive showing in three starts.

"We felt like he's ready," manager Bob Melvin said. "We feel like this could be a nice little shot in the arm for us. We tried to get this guy ready and back, and when he was ready, we said we'd get him here, because he is so talented. We're looking forward to watching him tomorrow."

Anderson made six rehab starts in the past month, compiling a 4.62 ERA during that span while regaining feel for his pitches. He's expected to throw no more than 100 of them Tuesday.

"It's exciting," Anderson said. "It's a lot of hard work and a lot of days put in to get to tomorrow, but hopefully it all pays off with a good outing.

"I'm confident. You have to be. If you go out there and are timid and scared, it's going to show up on the field. I like where I'm at. It'll be fun to pitch in front of a crowd and against a big-league team rather than in front of 350 people in New Orleans."

Anderson's last memories of pitching on a big league mound aren't too fond, having given up a combined 15 runs in 10 1/3 innings to the Yankees and Red Sox, before succumbing to injury after his start against the latter on June 11 last year. But his confidence, like his health, is back, and much of that stems from the organization's belief in him to immediately contribute to a contending team.

"These are meaningful innings, so I want to go out and pitch well, because we need to win ballgames," Anderson said. "So it's going to be that much more pressure-filled, but I wouldn't have it any other way."

The lefty, who was wanted by a handful of teams near the Trade Deadline, is a prized possession in Oakland, where he signed a four-year deal -- with team options for 2014 and 2015 -- worth $12.5 million in 2010, having compiled just 32 career starts up to that point. Anderson responded in fine fashion, finishing the season with a 2.80 ERA, before making just 13 starts in a shortened 2011 season.

Since, Anderson has dropped nearly 25 pounds, taking full advantage of the time away from the mound in hopes of returning to it in better shape.

"I feel strong, I feel healthy, and hopefully it translates to good things," Anderson said, before entering sarcastic mode. "Who knows? If it doesn't, maybe I'll go try to eat cheeseburgers and get fat."

"These Tommy John surgeries, these guys come back stronger and better at times and will sometimes throw harder at times," Melvin said. "He's worked very hard, is in much better shape than he was in. Everything that we've seen and the way he's feeling would suggest that he's ready to go."

Melvin, asked several times over the course of the last month about the possibility of a six-man rotation upon Anderson's return, said Monday that the club is not "in a position to do anything but [a five-man rotation]" for now, noting that it's tough to do before rosters expand in September.

In the meantime, Anderson isn't worried about how many days will separate his starts. He's simply focused on one day.

"It definitely feels like it's been awhile," he said. "You can't go out there tomorrow and worry about mechanics, about your elbow. You just have to go out and get people out and do what you can to help your team win."

Worth noting

• Outfielder Seth Smith, stationed on the disabled list since Aug. 3 with a strained left hamstring, is slated to start for Triple-A Sacramento on Monday night. If all goes well, the A's could see him sooner than later.

"There's always a chance, if he feels good, he could be back here tomorrow," Melvin said. "We're going to try to get him back as soon as he feels comfortable."

• Donning Petaluma National gear in the A's clubhouse on Monday afternoon, outfielder Jonny Gomes watched his hometown team walk off against New Jersey to advance in the Little League World Series, leading teammate Brandon Inge to deliver a pie to a thrilled Gomes' face.

"That was pretty cool," Gomes said. "Probably the first ever pregame pie in the history of the game."

The A's have witnessed plenty of the postgame type, having tallied 13 walk-off wins this season.

"I don't know if we're watching them or they're watching us, but it's pretty similar," Gomes said. "It must be in the water up here."