PHOENIX -- Typically when Sept. 1 comes around, teams add youth to provide a shot in the arm for the final month of the season. But this year, the D-backs are hoping to get three mainstays back from the disabled list when the roster expands to 40.

D-backs pitchers Takashi Saito and Josh Collmenter and infielder Willie Bloomquist are all making strides to rejoin the team.

Collmenter, recovering from ulcers, and Bloomquist, battling a stiff back, could be ready as soon as Saturday, when the club is in Los Angeles.

"I'm hoping and expecting that they will be with us," D-backs manager Kirk Gibson said. "We're hoping those two guys are healthy, maybe a couple more beyond that."

Collmenter, who has pitched four scoreless rehab innings in the rookie-level Arizona League, is scheduled to throw again Tuesday. Bloomquist's plan is more up in the air.

The veteran went 0-for-2 on Monday in his second rehab game and will play again Wednesday, but his status for Tuesday is undetermined.

"We'll see how he feels," Gibson said. "He felt really good yesterday and feels good today so far. But if he's not ready to play, I don't know if we'd activate him."

Saito, on the DL since Aug. 14 with a strained left hamstring, will also pitch in one of the two games, according to Gibson.

D-backs won't add Bauer until Reno's season ends

PHOENIX -- Although D-backs top prospect Trevor Bauer will likely see action in the Major Leagues again this season, it won't be in the immediate future, as manager Kirk Gibson said Tuesday the club wants the 21-year-old to stay in Triple-A until Reno finishes its campaign.

Entering Tuesday, the Aces were four games ahead in their division with seven games remaining.

"If our staff stays healthy, we wouldn't bring Trevor up until they are done," Gibson said. "If they get in the playoffs, I'm sure he'll stay with them."

The Pacific Coast League postseason begins Sept. 4 and runs through the 16th for the championship series.

On Sunday, D-backs general manager Kevin Towers also said he expects Bauer to be back with the team.

"I'd imagine he'll at least get a start or two," Towers said. "We'll see. We'll watch the innings the other guys have. [Patrick] Corbin has more innings than most. Once we get into September, we'll see where we are."

While Bauer struggled in his four-outing stint with the D-backs earlier this season, allowing 11 earned runs and walking 13 batters in 16 1/3 innings, the right-hander has bounced back in Triple-A, staying in the strike zone more.

In his last two starts, Bauer tossed 16 innings, handing out just two walks.

"I know he worked on some things," Gibson said. "We communicated with him that we would like him to be more efficient with his pitches. They are trying to miss the bat sometimes too much, the next thing you know you walk a guy and you used all those pitches. They start accumulating, it doesn't allow you to go very deep."

Goldschmidt's rare day off opens door for Wheeler

PHOENIX -- Over the weekend, D-backs manager Kirk Gibson applauded Paul Goldschmidt's durability and said he had no plans to rest his first baseman at the moment.

What a difference a few days and a tough right-hander can make.

Facing Reds National League Cy Young Award candidate Johnny Cueto on Tuesday, Gibson gave Goldschmidt his first day off in 34 games, replacing him with left-handed batter Ryan Wheeler in the lineup.

"He needs a little break, give him a little mental break as well, he could still contribute in some capacity as well," Gibson said. "I've got all my lefties in the lineup."

Even though his name wasn't penciled in, Goldschmidt still prepped Tuesday like he would be starting.

"He'll be prepared for sure, he tries to prepare for himself and his teammates," Gibson said. "You see a lot of conversations between him and his teammates during the games. He'll certainly be aware of where he might be asked to swing the bat within the game."

The decision to rest Goldschmidt gave Wheeler a chance to showcase his abilities at a new position. He had previously only appeared at third base in the Majors, but made 32 starts at first for Triple-A Reno earlier this year.

"I've got some time over there, not too much here, but I've always felt good there," Wheeler said. "I take ground balls there once every four days. Obviously not the majority of the time, but I should be fine over there tonight."

Wheeler entered Tuesday without a hit in his last four games but has put together quality at-bats, which has given him confidence even though the results aren't coming.

"It's frustrating, obviously. You can do everything you want to do and still make outs," he said. "I know it's part of it and I feel like I've done a pretty good job of not pressing. I'll get some cheap ones here, pretty soon, or at least that's what you hope for."