BALTIMORE -- New Oriole Joe Saunders flew to Maryland on Monday and is expected to be officially added to the roster on Tuesday.

Right-hander Jake Arrieta, who was recalled from Triple-A Norfolk on Sunday to take the roster spot vacated by Matt Lindstrom, was optioned back to Norfolk following Monday's 4-3 victory over the White Sox. The Orioles' Opening Day starter, Arrieta reiterated that he has worked hard to change his mental focus.

"I don't think there's anybody more frustrated about the way things have gone than I am," said Arrieta, who worked hard to be 100 percent healthy this spring coming off season-ending right elbow surgery and was demoted after pitching to a 6.18 ERA in 18 starts. "Obviously, it's me out there. It's my stats, it's my outings that have affected the team. So, I'm pretty much trying to wipe the slate clean."

While Arrieta's stay was a short one, he is expected to be a September callup. The Orioles' roster will continue to change with the pending returns of Wilson Betemit and Jason Hammel, and the rotation is undecided beyond Chris Tillman starting on Tuesday.

Saunders will start Wednesday or Thursday with Zach Britton "probably" starting the other game, according to manager Buck Showalter. Asked where this leaves rookies Steve Johnson, who has pitched well in both of his starts, and Miguel Gonzalez, who has been arguably the biggest surprise of the season, Showalter said they remain candidates.

"Stevie's presented himself well against Seattle and Toronto," Showalter said. "We'll get Miguel in there at some point, I'm sure."

Hammel, Betemit nearing return to action

BALTIMORE -- Pitcher Jason Hammel threw 58 pitches in his second simulated game Monday afternoon and the plan is for him to go five innings in a rehab game Saturday as the Orioles continue to cautiously target a Sept. 6 return.

"This is another level," manager Buck Showalter said of why the club is having Hammel make at least one rehab appearance, likely for high Class A Frederick. "He's been out of this for a while. It's one thing to get him and Troy [Patton] back, it's another thing to know what level of performance you're going to get.

"It's not a given that just because they're back, they're going to pick up right where they left off. As many things as we can get a cheat sheet on before he comes back here, that's important. That's why we're trying to add some depth. I don't think anyone here assumes that Ham's going to pick up where he left off."

If Hammel, who had surgery on his right knee in July, does return on Sept. 6, he will likely be limited to the six-inning range.

The Orioles could also be helped by the return of Wilson Betemit as early as Saturday. Betemit, who is rehabbing an injured right wrist, joined the team Monday to hit outside and the plan is for him to go on a rehab assignment Wednesday.

"I want to see [how it feels] because I didn't get a chance to hit outside in Florida," said Betemit, who has been sidelined since Aug. 12. "They said today to see how it feels."

Orioles team up with Casey Cares Foundation

BALTIMORE -- Casey Cares child Kevin B., his family and friend got VIP treatment at Camden Yards on Monday, taking a tour of the stadium, watching batting practice and special tickets to the game in advance of his ninth birthday.

Kevin, who suffers with a rare blood disease, LCH, got a day out and away from his treatment at Sinai Children's Hospital and got to meet many Orioles players. It was also his first day of fourth grade.

The event was part of the Family Festivities Program of the Casey Cares Foundation, a charity that provides uplifting and ongoing programs with a special touch for critically ill children and their families.

"This is such an awesome afternoon for Kevin and his family to get away from their stressful routine," stated Casey Baynes, Founder of Casey Cares. "We are so grateful to the Orioles for making memories like this happen for Casey Cares children. They are a great team on and off the field."