PEORIA, Ariz. -- For Jarrod Parker, the question was never if he was going to be a big league mainstay but when.

One spring performance surely can't provide all the answers, but Parker used his first outing to reaffirm the A's thinking that his time could come soon -- very soon. After the righty fanned four in two no-hit innings against the Mariners in a 9-2 A's victory on Saturday, manager Bob Melvin said there's no question Parker has the chance to break camp in the rotation.

"He has to be a guy you consider for that," Melvin said. "His stuff is too good."

Parker, ranked by MLB.com as the A's top prospect, reached 96 mph on his fastball and demonstrated pinpoint command -- often difficult to achieve in the early stages of spring -- while also showing off a changeup and slider, the latter which hadn't seen much action since he underwent Tommy John surgery in October 2009.

"Definitely this early, having that command is a good sign," said Parker, the key piece in the deal that sent Trevor Cahill to Arizona this winter.

"You want to see that, absolutely," Melvin said. "To go out there and throw three pitches for strikes, going forward that's a good confidence boost for him, not that he needs it."

Parker threw just 25 pitches -- 16 for strikes -- and noted he especially felt good about being able to get back up for a second inning "since you never know how that's going to feel." Among the four to fall victim to his strikes was Ichiro Suzuki.

"You look in [the Mariners'] dugout," Melvin said, "and you can see them talking about him, too.

"He's a guy you know the other organization has always taken care of. I let him know nothing's changed awhile back. He's a guy we covet. For him to be able to go out in his first outing like that is pretty impressive."

Worth noting

• Right-hander Tyson Ross, also battling for a starting job, struggled with command in his Cactus League debut, walking two and giving up a run in just one inning. Ross was forced to throw 33 pitches, of which just 16 were strikes.

"Unfortunately I had a little too much movement," Ross said. "I was kind of missing some spots there, and I definitely have to make an adjustment next time out. I felt like I was coming out pretty easy and free, though, and threw some good changeups and a slider, so definitely some positives out of today."

• Jemile Weeks' continual work from the right side of the plate paid off Saturday, when he hit a home run to left field against Mariners lefty Hong-Chih Kuo.

• Monday's split-squad action will take right-hander Bartolo Colon to Tempe, Ariz., to face C.J. Wilson and the Angels, while Brad Peacock, the team's third-ranked prospect, stays at Phoenix Municipal Stadium for a matchup with the Cubs under the watch of manager Bob Melvin.

• Melvin said Friday he won't rely on Brian Fuentes and Grant Balfour's spring performances to decide who is best fit for the closer's role, given their long track records. Other moving pieces in the bullpen will affect his decision. For instance, if Fuentes exits camp as the only lefty in the bullpen, Melvin will likely go to a righty for the ninth-inning role. Right-handers Joey Devine and Fautino De Los Santos are also in the mix.