There is no doubt the San Francisco 49ers' focus in free agency, which begins Tuesday, will be to keep their own players: safety Donte Whitner, cornerback Tarell Brown and kicker Phil Dawson.But the 49ers will also likely bargain shop for a few pieces. Among the position they may look at is receiver. Last week, we looked at the possibility of the team considering Minnesota receiver Jerome Simpson. Another name to consider may be Kansas City Chiefs receiver Dexter McCluster.