OAKLAND -- Plenty of questions face the A's pitching staff, which is set to report to camp in less than three weeks.

Who will fill the back end of the rotation? Who will assume the closer's role?

Time will only tell, but Bob Melvin didn't necessarily need much of it to make another decision. Though nothing is set in stone, the A's manager hinted at FanFest on Sunday that Brandon McCarthy will start the club's Opening Series contest against the Mariners on March 28 in Japan, with fellow righty Bartolo Colon to follow in the second game.

Left-hander Dallas Braden, expected to return by mid-April, will ultimately join that crew. And, beyond that, "all of the other guys have the opportunity." Jarrod Parker, Brad Peacock, Tom Milone, Tyson Ross and Graham Godfrey are among those vying for a chance.

McCarthy, coincidentally, was among the fifth-starter mix just last year. Now, following an offseason that brought about the trades of All-Stars Gio Gonzalez and Trevor Cahill, he's standing at the front of the line.

"It would be a lot of fun," McCarthy said of potentially starting Opening Day. "I think it's one of those notches any guy wants to have at some point. It's certainly something you'd love to be able to do on a yearly basis -- where you're a lockdown guy and everyone refers to you as that, so that's an ultimate career goal. But to be able to do it would be great. And if I earn that honor, I'd be thrilled to have it."

McCarthy went 9-9 with a 3.32 ERA in 25 starts last year, compiling 123 strikeouts in 170 2/3 innings.

"If there's one mainstay in that rotation, right now, it's going to be [McCarthy]," Braden said. "The way he pitched in the second half of last year, he was near unhittable, in my opinion."

Barton won't be at full strength by start of camp

OAKLAND -- Daric Barton will have to outplay three other candidates this spring in order to regain first-base duties in Oakland. And for a few weeks, he'll have to do it while still rehabbing his surgically-repaired right shoulder.

Barton won't be at full strength by the start of camp, so he'll likely be limited to the designated-hitter role when exhibition games begin, he said on Sunday at FanFest. He won't be throwing at 100 percent until at least mid-March.

Still, Barton remains optimistic he'll be ready by Opening Day. He's been hitting off a tee, and will begin soft toss and live hitting this week, as he prepares for a season he hopes will include improved offensive numbers.

The 26-year-old hit just .212, with no home runs and a .268 slugging percentage, in 67 games for the A's before he was optioned to Triple-A Sacramento on June 22.

"There wasn't any production last year," Barton admitted. "That's something that needs to improve. There were some things hindering my swing last year, which I believe we fixed, and I look forward to competing for a job.

"I want to help the team. I'm healthier now than before."

Brandon Allen, Kila Ka'aihue and Chris Carter are also in the mix at first base.