GLENDALE, Ariz. -- Two weeks away from the start of the season, most teams have a handle on what they expect to happen. At this point, most clubs are making the obvious decisions for the obvious reasons, and a month and a half hasn't changed anything. Take Saturday's A's-White Sox game: Jarrod Parker versus Chris Sale will be a marquee matchup in a few short weeks once the games start to count. So, even after the White Sox's 11-5 win over the Athletics in a sloppy slugfest, an ugly outing from his ace did not stop Sox manager Robin Ventura from making the non-controversial announcement that Sale was his Opening Day starter.

"We feel very confident with him going forward and giving him the ball for the first start. … It's something for him to be motivated [during] the last two weeks and get out there and go. He's ready to do that," Ventura said.

Well, of course Sale is going to start on Opening Day. That's what you do when a guy just won 17 games for you, a year good enough to finish sixth in the American League Cy Young voting. That isn't a decision, that's belatedly announcing the obvious.

A's manager Bob Melvin was similarly sanguine about Parker after his young hurler got knocked around for seven runs in three-plus innings.

“It certainly was as bad as the numbers would have indicated," Melvin said. "I think that we had some defensive issues that added to that. That's the difficult thing about spring; for some guys numbers do play out, for some they don't. Based on what he accomplished last year, he's not going to be evaluated on numbers."

Generally, performance in spring training isn't usually going to determine who wins a job, a new role, or the honor of an Opening Day start. But performance is going to wind up influencing those rare instances where there are decisions left to make, decisions that weren't already made in December or January as a function of who a team has signed and why. Welcome to the A's world, where with just two weeks left, they don't know for sure who will be getting playing time at second, short and third.

As Melvin observed about sorting out his muddled infield picture, "There's a good chance it won’t play out until the very end," he said. Now that's a decision.

The A's came into camp with no established answer for who would be their starter at second or third, and with a question mark at shortstop. They got little in terms of offensive performance from those slots last year: a .671 OPS from their third basemen, .620 from their second basemen and .585 from their shortstops. Winning the AL West last year, incredible as it was, was done despite their infield's production, not because of it.

Getting Jed Lowrie from the Astros in a trade was the big step to address some part of the problem, and signing Japanese league veteran Hiroyuki Nakajima was supposed to give them a shortstop. At second base, the hope was that getting Scott Sizemore back from missing all of 2012 with an injury might give Jemile Weeks some competition at second.

Then Weeks missed almost two weeks with a bone bruise on his shoulder, while Sizemore injured his hand and has struggled with that over almost the exact same stretch. With two weeks to go, it's still an open question whether the A's have an answer at second base, or perhaps any of the three positions.

Because of Lowrie's positional flexibility, you could see this as a case where several players are in direct competition for playing time and roster spots, albeit not for the exact same job. It isn't like Melvin has any slam-dunk obvious choices. It's a situation where a dark-horse candidate can enter the race, expanding rather than narrowing his options. Focusing on Sunday's game, Melvin said, "Eric Sogard will start at second today, and some other guys are doing well, making it tougher to actually narrow it down. Sogard has sneaky pop at times, depending on the ballpark. We've seen him hit a few home runs in the last couple of years, but he's more a gap-to-gap guy, and does get the head of the bat out a little down the line for some doubles."

So things are already getting interesting. Unfortunately, Lowrie can't play everywhere at once simultaneously -- he can only plug one hole at a time (assuming he's healthy). And that could be an even bigger problem because on defense Nakajima is far from a sure thing at shortstop, which might force Lowrie into some time there.

The nicest thing you could say for Nakajima on Saturday is that he followed up a first-inning error with doing a good job on an inning-ending double play, taking the feed from Sizemore with the bases loaded to get Parker out of the inning. Nakajima also blew the tag on a sacrifice bunt in the second, although a sailing throw from catcher Derek Norris didn't help (Norris got the error).

Melvin came to his likely starting shortstop's defense, but he has to -- it’s his job. Melvin observed, "It's been a tough time for him. Whether it's the culture shock, being with a new team, playing in a new league, all these things play into it. Each guy takes that at his own speed. There's something to be said about getting acclimated, and maybe he's not all the way there yet, getting comfortable out on the field."

Questions about Nakajima's defense are unavoidable considering that all of the other, more highly regarded defenders at short who have come over from Japan have failed. Add in that Nakajima hasn't looked good at the plate in Cactus League action, and the assumption that he was going to be their regular shortstop might be revisited by the end of the month.

Melvin focused on the positives about Nakajima's resilience as he tries to adapt, saying "He's very personable, he's always in a good mood. He works very hard, but I think to an extent, he still has to kind of find his way and get comfortable, both offensively and defensively."

Keeping things upbeat makes sense, but there again, that's Melvin’s job. But in another couple weeks, he'll have to make a series of tough overlapping decisions. While obvious calls like Sale getting tabbed for an Opening Day assignment get headlines. Two weeks of performance might seem an irrational basis to make a decision when teams know everything there is to know about their players' histories, but that's what the A's have left to work with.

Christina Kahrl covers baseball for ESPN.com. You can follow her on Twitter.