PEORIA, Ariz. -- Promising rookie prospects Michael Pineda and Blake Beavan will be the starting pitchers Friday when the Mariners conduct their lone intra-squad game of Spring Training.

Pineda, 22, has been getting plenty of publicity as a legitimate contender for a rotation spot, with the massive right-hander opening eyes with a fastball in the upper-90s and a quality slider as well.

Beavan, also 22, is another big youngster at 6-foot-7, 240 pounds. Acquired in the Cliff Lee deal last July, he finished last year at Tacoma. And while he's likely ticketed for a return to Triple-A, the Mariners are taking a good look this spring and have liked what they've seen thus far.

Both Pineda and Beavan threw strong bullpen sessions on Wednesday in preparation for their one-inning starts. The intra-squad game is scheduled for five innings on Field One at the team's practice complex, with 10 different pitchers to throw an inning apiece.

Team One's rotation will be Pineda, Dan Cortes, Fabio Castro, Chaz Roe and Jose Flores. Team Two's pitchers will be Beavan, Josh Lueke, Edward Paredes, Yoervis Medina and Tom Wilhelmsen.

Manager Eric Wedge said he'd try to get all the position players a couple innings of work.

While Wedge said there's no big significance to the pitchers chosen, obviously the club is intrigued by Pineda and is eager to see Beavan right out of the box as well.

"You love his size and I really like the way his arm works," Wedge said of Beavan, a first-round Draft pick by the Rangers in 2007. "It's fun to watch a young person like that continue to learn and get better. I liked watching both he and Michael throw their bullpen today, just working. They're doing what they're supposed to be doing right now."

The Mariners will host a FanFest on Saturday from 11:15 a.m. to 1:15 p.m. MT at Peoria Stadium, with about half the team conducting a workout and signing autographs.

Things then turn up another notch Sunday with the annual charity game against the Padres kicking off the Spring Training schedule at 1:05 p.m. MT (12:05 p.m. PT).

Wedge said the pitching rotation for Spring Training games will be forthcoming in the next day or two.

Zduriencik says rotation still a question

PEORIA, Ariz. -- Mariners general manager Jack Zduriencik looks around the American League West and sees solid rotations in Oakland, Texas and Los Angeles. As for the Mariners, they're working hard to get there, he said, with some question marks still to be determined this spring.

"If you look at each staff, they're healthier and more concrete than what we are," Zduriencik said. "You know what Texas is going to be. You know where Anaheim and Oakland are. We're still in that figuring-out process right now."

Mostly what the Mariners are figuring is who is going to fill the fourth and fifth spots in the rotation behind returners Felix Hernandez, Jason Vargas and Doug Fister.

Erik Bedard has been impressive in the first 10 days of camp, but remains a question because of his injury history. Michael Pineda is an imposing presence, but he's also a 22-year-old rookie with no Major League experience. Then there are returners Luke French and David Pauley and non-roster invitee Nate Robertson, as well as a host of young prospects in camp.

"Where we stand right now it's still a question of how it's all going to fall together," Zduriencik said. "I don't have the answer for that. We won't know until the games start and we break and take the 12 best pitchers north with us.

"I have my ideas and thoughts and feelings, but I'm not going to put limitations or expectations on anybody. The pitching will work itself out. I have a watch-and-see approach. Health is an issue and how quickly some guys grow up. And some of these veteran guys are coming in trying to make a statement. To me, we'll see what happens."

Aardsma about a week away from throwing

PEORIA, Ariz. -- Closer David Aardsma was walking without crutches for much of the day Wednesday, but says he's still probably a week away from beginning to throw as he returns from labrum surgery on his left hip.

Aardsma, 29, took a cart out to the practice field as he's been doing all camp, but this time, he walked the length of the field without any aid and then went between several fields as well before taking the cart back to the clubhouse.

He spent most of the day carrying the crutches instead of using them, having been told to rely on them for the next few days only when his hip starts tiring. For the most part, however, he's about ready to take the next step toward actually throwing again for the first time since his surgery in early January.

"I'm excited. It was a good day walking and progressing," he said. "Walking feels normal again."

He won't be pitching any time soon, however. He'll start his throwing program from ground zero and need to work his way back up to playing catch on flat ground, then extending to long toss, eventually moving to the bullpen and finally the regular mound in game action, a process that figures to take at least two months. But first things first.

"Right now the plan is to take maybe about a week and really get comfortable walking and rotating and getting my body in the right direction, so when we start throwing, there are no setbacks," he said. "I think it's smart to not jump into something before my body is ready."