The A's play their first game Saturday since falling in Game 5 of the Division Series against Detroit, and the team's new shortstop, Hiro Nakajima, will take part in his first game as a big-leaguer. In the wake of Nakajima's signing, scouts said the biggest questions about Nakajima were about his defense, but A's manager Bob Melvin and infield coach Mike Gallego have been pleased with his work at shortstop during spring drills. The bigger questions once games start, as far as Melvin is concerned, will be about what other things Nakajima can do to help the team. "Is there foot speed there to steal bases? Is he a hit-and-run guy or a guy that you want to let him drive in runs?" Melvin said. "There are a lot of unknowns. We've seen the skill set here. You really don't get a good feel for it until you see him in game." Also in the lineup Saturday: Jemile Weeks, who will bat leadoff, right in front of Nakajima, and play second base. Weeks is in a head-to-head battle for the starting spot with Scott Sizemore, who will DH Saturday. There are others in the race, too, with Adam Rosales, Andy Parrino and Grant Green among the hopefuls, but Weeks, the starter much of the past two seasons, and Sizemore, back after missing a year with a knee injury, are the front-runners.