Courtesy of an ’07 draft-day trade to grab S Eric Weddle, an ’07 supplemental draft pick of CB Paul Oliver and a midseason trade to acquire WR Chris Chambers, a talent-laden Chargers squad had limited picks — especially high picks — with which to improve. With Drayton Florence gone to Jacksonville, San Diego’s top selection was Thorpe Award-winning CB Antoine Cason, who should be a solid nickel back immediately. Cason lacks the athleticism of starting CBs Antonio Cromartie and Quentin Jammer but excels in zone coverage. CB DeJuan Tribble is similarly equipped to handle zone coverage, although his lack of size and speed are liabilities. With Michael Turner now earning his paycheck in Atlanta, there was a considerable need to provide LaDainian Tomlinson with a capable backup running back. The Chargers added two, showing just how significant a void there was. FB-RB hybrid Jacob Hester runs with a bullish style that allows him to pick up yards after contact, and he’s a serviceable lead blocker, too. Marcus Thomas is a bit more natural as a runner, although he’s mostly a north-south guy. OT Corey Clark cut his teeth playing against the defensive ends of the Big XII, but his lack of quickness makes a move to the interior at the pro level a distinct possibility.