The Chargers have warned wide receiver Vincent Jackson and left tackle Marcus McNeill that their salaries will be reduced if they don't sign their contract tenders before June 15. San Diego general manager A.J. Smith confirmed to the Union-Tribune that the players were sent letters. According to the newspaper, Jackson's salary would be slashed from $3.268 million to $583,000 if he doesn't sign by next week and McNeil's pay would drop from $3.168 million to $600,000.