But when the A's and Padres met Monday afternoon in Peoria, Tyson Ross was wearing a Padres cap, facing -- as he playfully called them -- "the guys in the white cleats."
So how did he get there?
Well, 2012 was a nightmare year for Ross. The tall right-hander posted a 6.50 ERA in 18 appearances (13 starts), and his WHIP skyrocketed to 1.81. Worse, his role with Oakland became muddled, and he began to lose confidence, spending five separate stints with Triple-A Sacramento and shuffling from a starting job into the bullpen.
"It was awesome pitching in Oakland, but at the same time, I'm happy to be here," Ross said. "Everything that happened last year, I have that in the back of my mind -- that's not going to happen again. I've been there; I know the mistakes I've made."
The light at the end of the tunnel came in the form of a trade to San Diego in November. The Padres shipped Andy Parrino and Andrew Werner to Oakland in exchange for the flame-throwing righty with the high ceiling.
That move gave Ross a fresh start with San Diego and -- at least for now -- a defined role as a starter. He is currently in competition for the Padres' No. 5 spot in the rotation, and with outings like Monday's -- three scoreless, two hits, three Ks -- he figures to be a front-runner.
"It's been huge," Ross said of the move to San Diego. "It's been great for my confidence. The coaching staff here believes in me. It's a fresh start -- new team, new guys. It's just hitting the reset button, you know."
No one has had a bigger impact on Ross thus far than Padres pitching coach Darren Balsley, who has given Ross plenty of input in his own development. For every tip Balsley gives Ross, he expects feedback, and if it's contradictory, even better. The two communicate and work from there.
"It tells me he wants to be a dominant Major League pitcher instead of just a survivor," Balsley said. "I get a feeling he wants to be dominant. He does know he's very talented, and I don't think he wants to be a guy who just is a swing man on the staff."
Balsley and Ross have been working to simplify his repertoire a bit. Ross came to San Diego with three different types of fastballs -- a two-seamer, a four-seamer and a sinker. To better command the fastball, Balsley insisted that Ross simply focus on the two- and four-seamers.
Ross also possesses a changeup, which he and Balsley have been working on slowing down to create more deception. One pitch Balsley says he is not tinkering with, however, is Ross' slider, "because there's nothing wrong with his slider. It's a very, very good Major League pitch."
That slider was on display for the Padres last June when they went to Oakland, only to be no-hit by Ross for 5 2/3 innings. That night was the first time Padres catcher John Baker got a look at Ross.
"When he gets that aggressive attitude, and he gets 100 percent confidence in his ability, I think you're talking about -- stuff-wise -- a top-five pitcher in the big leagues," Baker said.
Ross' combination of an upper-90s fastball and a slider with bite makes Baker think Ross could be a 20-game winner with the right mindset and aggressiveness.
Balsley and manager Bud Black each gushed when asked what they thought Ross' ceiling could eventually be.
"This guy was a high-profile guy in college; he's still mid-20s with a lot of potential up-side," Black said. "I think it's going to have to come back to his throwing pitches in the strike zone."
He struggled with that a bit Monday. Even with the very solid outing, Ross needed 62 pitches -- 38 strikes -- to make it through three innings.
But every time Ross ran into trouble, he managed to work his way out of it -- something he was not always able to do in 2012.
So what has been the biggest difference in Ross' changed mindset this spring?
"It's just experience," Ross said. "There's no substitute for it. As you go about living your life -- different experiences good and bad -- you just take them as they come, and you learn from them. "I don't think there are any mistakes. There's just something negative that happened, and you learn from that and you're better because of that."