OAKLAND -- A's left-hander Dallas Braden, who was placed on the 15-day disabled list with left shoulder stiffness on Monday, will be evaluated by noted orthopedic surgeon Lewis Yocum in Los Angeles on Wednesday.

Until the results of that visit are revealed, the A's won't know the extent of Braden's injury, which marks the first time he's experienced shoulder problems in his big league career.

The 27-year-old exited Saturday's start after five frames and paid a visit to the team orthopedist on Sunday but walked away without any definitive answers, leaving the A's still hopeful that it's nothing of the long-term sort.

Braden, now enduring the fourth DL stint of his career, was 1-1 with a 3.00 ERA in three starts this season, yielding 18 hits while racking up 15 strikeouts and five walks.

Right-hander Tyson Ross, who has made three appearances out of the bullpen this season, will take Braden's place in the rotation beginning Friday in Seattle.

Ross assumes Braden's spot in rotation

OAKLAND -- Young A's righty Tyson Ross, who lost out on the lengthy fifth-starter battle out of spring, has found his way back in the rotation sooner than expected, as it was announced on Tuesday that he'll take the rotation spot of the injured Dallas Braden on Friday.

"I'm excited," Ross said. "I'm looking forward to the opportunity to start again."

Ross, whose first start of the 2011 campaign will coincide with his 24th birthday, began the year on Triple-A Sacramento's roster but was called upon by Oakland before he made an appearance for the River Cats to join a bullpen void of Michael Wuertz (hamstring).

Ross has not allowed a run in two of his three relief appearances after going 1-0 with a 0.59 ERA and 10 strikeouts through 15 1/3 innings spanning five Spring Training outings, all of which saw improved fastball command, along with an extra dosage of confidence.

"He threw the ball great all spring, was pretty close to making rotation out of spring, and we think the world of him," A's manager Bob Geren said. "You look at the rotation, and you'd like to get a guy that has good fastball movement and a swing-and-miss breaking ball.

"You look at velocity, he has well-above-average velocity with a little deceptive delivery and pretty good movement. If he pounds the zone, he'll be tough. That's what he did so well this spring."

Ross was a surprise roster pick out of camp last year and made 26 appearances -- two starts -- with the A's before being sent to Sacramento at the beginning of July to get stretched out as a starter. The hard-throwing right-hander was shut down in August because of a strained right elbow, but his regained health has allowed him to resume starting duties again.

That role is what the A's envision for their 2008 second-round Draft pick, and it's what Ross admittedly prefers, though he noted he simply wants "to pitch in the big leagues."

"I'd like to hold down a role as a starter," he said. "I'd like to do that long-term."

But he's still learning. Ross said he closely watched pitching performances in the 2011 playoffs -- particularly Roy Halladay -- because "that's the best baseball that's played all year."

"Last year, I learned I can pitch here at this level," he said. "I've watched a lot of guys and how they attack hitters, and I'm hoping to put that into practice."

The A's will have a better idea of how many more starts they expect out of Ross following Braden's visit with Dr. Lewis Yocum in Los Angeles on Wednesday, when he'll be evaluated for a stiff left shoulder that sent him to the disabled list on Monday.

Purcey's addition gives A's 'pen five lefties

OAKLAND -- With Monday's addition of reliever David Purcey, the A's bullpen is now operating with five lefties -- a rarity for any team.

But manager Bob Geren has no qualms about his staff, simply stating on Tuesday, "It is what it is."

"We have our best seven guys out there," he said, "and I'm happy with it."

Purcey, who was traded to the A's by the Blue Jays for Minor Leaguer Danny Farquhar, was designated for assignment by Toronto last week after making five appearances, including two against the A's in the first week of the season, fanning three in a combined 1 1/3 scoreless innings.

Purcey had yet to allow a run this year until his most recent outing against Seattle, when he surrendered three in one-third of an inning.

"I like what I saw in Toronto a lot, and when I heard his named mentioned I was all for it," Geren said.

Purcey will be used "just like any other reliever," the A's skipper noted. The 2010 campaign marked his first out of the bullpen following a successful transition from starting duties, as he posted a 3.71 ERA with 32 strikeouts and 15 walks in 34 frames.

"My best year was out of the bullpen," he said. "That's the first year I've felt real comfortable."

In three big league seasons, Purcey has yielded a .275 opponents' batting average against right-handers, compared to a .226 mark when facing lefties.

On Tuesday, Purcey expressed excitement in landing an opportunity with another team, not to mention gratefulness for the awarded days off in his hometown of Dallas following his designation. His wife, Kate, is due to give birth to the couple's first children -- twins -- in July.

"It was nice getting a little time with family to regroup and gather," he said. "Now I can go on from here.

"They have a lot of good players here. I've heard good things, and I'm excited to come over and try to contribute."

Wuertz set for one more rehab outing

OAKLAND -- Right-hander Michael Wuertz, fresh off a one-inning stint with Class A Stockton on Monday, when he struck out the side, came into the A's clubhouse on Tuesday feeling "incredible."

Wuertz, nursing a strained left hamstring, is eligible to be reinstated from the disabled list, but the A's want him to garner another rehab appearance. So he'll do just that on Wednesday in Reno, where he'll undergo an extended outing -- four or five outs but no more than 40 pitches -- with Triple-A Sacramento.

"That's the plan for now," A's manager Bob Geren said, "and then we'll go from there."

"I'm going by what they say," Wuertz said, "but if it was up to me, I'd like to be activated right now."

The 32-year-old reliever had endured one other outing with the Ports before Monday's three-strikeout performance, struggling in one inning of work by way of three runs on four hits, including a home run.

"I feel way better," Wuertz said. "I hadn't thrown off the mound in two weeks at that point, but I feel like I'm back to where I need to be now."

The veteran hurler, coming off a 2010 campaign in which he posted a 4.31 ERA, had appeared in just one game this season before suffering the injury. He tossed one shutout inning with two strikeouts against the Mariners on Opening Night.