The Mariners took a chance on Matt Lawton, agreeing Thursday to a $400,000, one-year contract with a player who will start next season under suspension because of steroid use. The commissioner's office announced Nov. 2 that Lawton tested positive for steroids, a substance identified as boldenone, which is used by veterinarians. "I made a terrible and foolish mistake that I will regret for the rest of my life," Lawton said at the time of his suspension. Because he tested positive under the 2005 program, Lawton will miss the first 10 days of next season instead of 50 games, the penalty called for under the toughened agreement players and owners adopted under pressure from politicians.