It is amazing how roster issues always seem to fall into place right at the end of camp. In the bottom of the first inning today, Wilson Valdez went into the hole at shortstop to snare a hot grounder by Detroit’s Gary Sheffield, planted, and threw to second trying to force Placido Polanco. The throw got there a fraction of a second late, and Polanco slid into Ramon Martinez’s right ankle. Martinez then hopped away in obvious pain before eventually being led off the field by trainer Stan Conte. Martinez has a mild sprain, and it isn’t clear how long he’ll be out. But if he begins the season on the DL, Valdez, who is hitting .377 and is out of minor-league options, will be the guy who takes his roster spot. Even if Martinez IS good to go, Valdez also would make the club if Rafael Furcal’s sprained left ankle hasn’t completely healed. Tigers 3, Dodgers 0, top 4, on a three-run homer by Sheffield.