Jon Gruden has built his reputation on the ability to rejuvenate the careers of veteran quarterbacks, such as Rich Gannon in Oakland and now Jeff Garcia in Tampa. The knock against him is that he’s been unable to work his magic on a neophyte. We hear, however, that he’s determined to finally groom a young quarterback, and rookie QB Josh Johnson has been targeted as the one case Gruden finally will crack. Sources indicated Johnson’s skills fit right into the head coach’s scheme — he’s smart and makes sound decisions. Last year at Division I-AA San Diego, Johnson threw just one interception and 43 touchdowns. With Garcia, Brian Griese and Luke McCown entrenched as the top three signalcallers on the roster, Gruden won’t have to rush the development of Johnson. “We have a chance to do some things with (Johnson), over time, if he does what he’s supposed to do with the ball and makes good decisions,” Gruden said in a post-draft assessment.