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8/7/2013 5:43 P.M. ET

Cautious A's schedule another sim game for Anderson

CINCINNATI -- Though all signs pointed to Brett Anderson beginning a rehab assignment this week, the A's have yet to decide when that time will actually come, as they continue to be guarded with their lefty.

Anderson threw live batting practice for the second time in four days Tuesday, this time without a screen in Stockton, Calif., home of the Class A Ports. He threw two sets of 31 pitches "and everything went fine," manager Bob Melvin said Wednesday.

Despite already building up to nearly 70 pitches, Anderson is scheduled to throw his third simulated game Saturday, rather than make a rehab start.

"We're really trying to make sure he's able to handle it with the foot," Melvin said. "We've been down this road once before, too, and [the injury] came back, so we're being pretty careful with that."

Anderson suffered a right ankle sprain that forced him to miss a start in April, only to enter the game in relief and pitch 5 1/3 innings of a 19-inning win against the Angels. Ultimately, the injury turned into a stress fracture in his right foot, and he hasn't pitched since.

Callaspo exits with forearm injury after play at plate

CINCINNATI -- A's second baseman Alberto Callaspo exited Wednesday's 6-5 loss to the Reds because of a left forearm contusion and is considered day to day, though he believes he'll be fine for Friday's series opener in Toronto.

Callaspo suffered the injury on a play at the plate in the fourth, when he was tagged out trying to score from second on a Stephen Vogt single. He was replaced by Eric Sogard at second base in the bottom half of the inning.

Before his departure, Callaspo collected two doubles in as many at-bats off Reds righty Homer Bailey, not only marking his first hits in an A's uniform, but also snapping an 0-for-18 streak.

"I'm just trying to do my job," Callaspo said.

"It was great," said Josh Donaldson of Callaspo's offensive showing. "Playing against him for the last couple years, he's one of those guys that grinds on you, battles you, and if you make a mistake, he has the chance to leave the yard. For him to get rolling, hopefully that's going to help our team."

Top prospect Gray could make first start Saturday

CINCINNATI -- The A's have yet to announce a starter for the second game of a four-game set in Toronto on Saturday, but all signs point to top pitching prospect Sonny Gray getting the nod.

The team has yet to say as much, but that just so happens to be Gray's day to start for Triple-A Sacramento. The other obvious candidate, lefty Tommy Milone, is still scheduled to start for the River Cats on Thursday after being optioned over the weekend, according to manager Bob Melvin.

It would mark Gray's first start as a big leaguer after the 2011 first-round Draft pick got a small taste of the Majors in July by way of a pair of relief outings. He pitched four scoreless innings for the A's, giving up two hits with six strikeouts and one walk.

Gray, who has a 3.42 ERA at Triple-A this year, last pitched Saturday for Sacramento, allowing three runs on eight hits in 6 1/3 innings. He struck out three in the outing and walked two.

By having Gray, or another arm, throw Saturday, the A's can give Sunday starter A.J. Griffin six days of rest. Jarrod Parker will start the opener Friday, with Dan Straily rounding out the series Monday.

Despite struggles, Melvin sticks with usual platoons

CINCINNATI -- Though he hinted at some lineup changes following another woeful offensive performance Tuesday night in Cincinnati, A's manager Bob Melvin didn't stray from his usual platoons for Wednesday's series finale.

Rather than Melvin shaking up the lineup, he stuck with the usual lineup against a righty pitcher, Homer Bailey, with Stephen Vogt starting at catcher instead of Derek Norris, who hit a pinch-hit solo homer in the ninth inning Tuesday night -- the A's only run in their past two games.

They've scored just 10 runs in their past six games, leaving 45 men on base in that span while hitting 4-for-42 with runners in scoring position.

"There's a tendency sometimes when you're not swinging well," Melvin said, "to mix things up too much, when we do have a plan here, a formula of how we run our team out there on a particular day."

The only prominent left-handed hitter out of the mix on this day was Josh Reddick, who sat in favor of another lefty swinger in Seth Smith. Reddick is hitting just .152 over the last 21 games and entered the day with a .205 clip on the season.

Melvin also opted to go with the switch-hitting Alberto Callaspo over the hot-hitting Eric Sogard, riding a 12-game hitting streak, at second base. Callaspo came into the game 0-for-his-past-18, including 0-for-11 with the A's. He recorded two doubles off Bailey, but then had to leave the game with a left forearm contusion, suffered in the fourth inning on a play at the plate.

"We'll stay with our matchups," Melvin said. "There are times when, even more so, you have to stick with it. There becomes a point where you shake things up just to have a different look, but this team was set up a particular way, and you're going to go through some struggles. I think, if you stay with those matchups, that they tend to even out at some point."

Worth noting

• Lefty reliever Jerry Blevins gave up his 10th run in his last 16 appearances Tuesday night, though Melvin is seeing signs of improvement with the southpaw.

"He's been getting better," Melvin said. "His stuff is crisper, and he looks more confident on the mound. Earlier, when he was really struggling, you could see he was picking a little more, as opposed to attacking hitters. I do see that confidence back where he's attacking hitters."

• The A's will play four games in Toronto, including three during the day, in a wraparound series that begins Friday and concludes Monday. During that time, Melvin will write out his lineup with Rogers Centre's artificial turf in mind.

"There's the challenge of keeping guys off the turf," he said. "[I] might need to DH somebody that could be affected by it more so than others. We'll take a look at that and see how guys are feeling each and every day."

Among those likely to get a day off on the field at some point are infielders Josh Donaldson and Jed Lowrie.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.