KANSAS CITY, Mo. (AP) – Dexter McCluster is back where he feels most comfortable.  That should make opposing defenses decidedly uncomfortable.  The 5-foot-8, 170-pound self-described “jitterbug” played mostly running back growing up, but he moved into a slot receiver role while becoming a multi-purpose star at Mississippi. When he was selected by the Kansas City Chiefs in the second round of the 2010 draft, the idea was to use him a similar fashion to college, putting him in the backfield and at times splitting him out wide.  He played mostly receiver last season, along with returning kicks and punts, but is shifting into the backfield again during training camp, and coach Todd Haley says he’s encouraged by his progress.  The Chiefs return to preseason action Friday night against St. Louis.