PHOENIX -- Jemile Weeks has had good spring showings before, so he wasn't about to get overexcited by a successful Cactus League debut performance against the Brewers on Saturday.

Still, Weeks had to be pleased with his day's work on both sides of the game, having notched a leadoff double in the first inning before making a fantastic diving play to start a double play in the second. These are scenes that will surely stay with Bob Melvin, who has the task of pinpointing an everyday second baseman by camp's end.

Weeks held that role at this time last year, but continuous struggles throughout the regular season prompted a demotion to Triple-A Sacramento in August. Since, Scott Sizemore has entered the mix at second base, and the club also has Jed Lowrie and Adam Rosales, among others, who can play the position.

The element of competition, missing from Weeks' spring last year following a remarkable rookie campaign in 2011, is back.

"There's definitely motivation," Weeks said. "I'm in a position where the word is you have to win your job, so I'm going about this like I need to win my job. It's a little different than knowing you have a job. It's a matter of trying to get ready now instead of getting ready for later."

Melvin will continue to watch Weeks closely.

"He got off to a great start last year and hit a couple of homers, and then just couldn't continue to ride that," he said. "He would never tell you he was banged up, but there were times when he was banged up. It starts with confidence, really, for him, and health, and then you go out there and let your ability to take over.

"He just has to get back to doing what he was doing the year before and going back to playing a solid defense as well. Sometimes when you're not hitting it's tough to focus on the total game, and everything can kind of go in a direction you don't want it to. He has the talent."

Weeks and Sizemore are likely to see the bulk of time at second base this spring. Sizemore will get the start there Sunday, after serving as designated hitter in Saturday's game. In that role he collected a single to find his way on base for the first time since 2011, after missing all of 2012 while rehabbing from a torn ACL.

Melvin would normally like to have his second baseman identified at least two weeks out before the start of the regular season, to allow time for him to find a comfort zone with the shortstop. But "whether or not that happens, I'm not sure," he said.

"Certainly you'd like to get to Spring Training, have your shortstop and second baseman and pair them together, and have them go through all the drills," Melvin continued. "But for now everyone will have to learn everyone. That's just the position we're in."

Everything goes smoothly in Nakajima's debut

PHOENIX -- The little nerves that accompanied Japanese shortstop Hiroyuki Nakajima in his first game as a Major Leaguer dissipated rather quickly on Saturday.

"The ground ball came relatively early in the game, so that kind of helped me alleviate the nervousness a little bit," Nakajima said through his translator. "Then I was second in the lineup, so I got to soak that up very quickly and early, too, which helped ease the tension."

Nakajima drew a walk in his lengthy first at-bat, and he went hitless in his final two plate appearances -- he popped out to second in the third and struck out swinging in the sixth -- but walked away after six innings of work against host Milwaukee feeling rather satisfied with the day's events.

"The environment, the ambiance, was just fantastic," he said, smiling. "It pumped me up. It was very exciting.

"Everything was within my boundary. It felt good to get the first experience out of the way. It was also very good to see actual live pitching. The more games I see, I think I'll gradually get comfortable."

The process isn't an easy one, but everyone around him is trying to do their part to make it so, and on Saturday it was Jemile Weeks who helped bring him along. The two teamed for a highlight-reel double play in the second inning.

"I knew that Weeks was going to get to that ball, so the rest was about how he was going to flip the ball, which area," Nakajima said.

"With the shortstop you have to trust him," Weeks said, "and we haven't played much together, but I tossed it up there where I thought he would be and he was there.

"It was good. We communicated well to make sure we're on the same page, and that's what you want right now."

Nakajima, too, deemed his communication with the day's second basemen, Weeks and Grant Green, "perfect."

"I thought he looked good, I really did," said manager Bob Melvin. "Made some good plays early on, looked smooth around the bases and worked well with Weeks. So far, so good."

Perhaps most impressive about Nakajima, showcased in his unofficial debut, is his awareness of facets of a big league game that will require adjustments. He noted that, while turning the double play, he was acutely observant of how the base runner was going to slide into second base.

"I understand that American base runners are aggressive," he said, "so while kind of getting away from the slide I just wanted to make an accurate throw to first base."

"He's a smart guy," Melvin said. "He's figuring things out, and nothing really panics him. It's going to take him some time to learn the opponent and so forth, but he's on the right track."

Nakajima had a familiar face watching him from the other side, with friend Norichika Aoki making a start in right field for the Brewers. The two spoke on the phone Friday, and promised to get together for dinner this spring.

Asked who will pay, Nakajima's smile widened and, citing his fellow countryman's lengthier tenure in the big leagues proclaimed, "Aoki!"

Chavez battles command, but strives to improve

PHOENIX -- The command issues that have plagued much of Jesse Chavez's big league career were back on display in his Cactus League debut on Saturday, but the right-hander is on a mission to thwart them moving forward.

The A's right-hander, awarded the first start of the preseason, walked two Brewers batters in as many innings and also gave up a home run to Ryan Braun in a 2-1 loss to Milwaukee at Maryvale.

"I thought his command wasn't where it should be," manager Bob Melvin acknowledged. "He was behind some guys, and gives up the one run, but probably got out of some innings that he doesn't need to get himself into."

The 29-year-old Chavez, acquired last August by the A's for cash considerations, faced a handful of pressure spots upon his arrival and allowed seven runs in 3 1/3 innings spanning four relief appearances with Oakland -- amounting to an 18.90 ERA and .474 opponents' average.

But the A's showed faith in Chavez by keeping on the roster amidst a constant wave of transactions this winter, a gesture that boosted the right-hander's confidence.

"The way the last couple offseasons have gone, it's kind of heartwarming, really," he said. "I knew where I was going to be, so it was just a very comfortable offseason. Being comfortable in the clubhouse is probably the biggest key. You can't go out there and perform when you're thinking about those things.

"I'm starting to feel a lot more comfortable. They welcomed me with open arms when I got here. That's always something you look forward to, having them accept you as a person and not just a player, because they already like you as a player."