It's too much to say that baseball becomes real Saturday with the start of the Cactus League for the A's. It's not too much to say that the level of baseball gets pushed up several notches, however, as the competition for regular season jobs begins in earnest with a road game in Maryvale against the Milwaukee Brewers. Will the opening day lineup have Jemile Weeks and Hiroyuki Nakajima up the middle and at the top of the lineup the way this lineup does? Will John Jaso be the starting catcher? Will Scott Sizemore have many chances as the D.H. after doing it Saturday? Will anyone supplant Brandon Moss at first base and Josh Donaldson at third base? These questions and more will play out over the course of the next five weeks in the lead-up to the regular season. "Don't play too much into this lineup," manager Bob Melvin said Friday. "You've got to stagger it, have at least four starters in every game." What Melvin wants to do is to turn his players loose, at least to some degree, and have them show what they do best and don't do best.