Security guards patrol every Chargers practice from a Murphy Canyon hilltop that overlooks the field, ensuring each session's privacy. Only the loudest practice sounds are heard up there. The occasional horn. The sporadic whistle. And, the past few weeks, maybe offensive line coach Joe D'Alessandris with his most important rookie. "He's on me a lot," D.J. Fluker said. "He's on me a lot because he sees the potential in me." The Chargers first-round pick is learning on the fly this offseason, recently concluding the 10-practice organized team activities (OTAs) phase while working with the first-team unit. The next step for the right tackle is a three-day mandatory minicamp that begins Tuesday. So, how is Fluker looking? That usually evokes a two-part answer at ground level. The first part: He is a rookie. "He's like any rookie," coach Mike McCoy said. "There's going to be some good and some bad to anything he does. You take the good with the bad. He's learning. It's like all rookies. They're learning a new system." The second part: If Fluker maintains this effort, he ought to be just fine. In June, the No. 11 overall pick naturally isn't where he'd need to be if this was September, and he knows that. He said he must improve his pass sets while keeping better pace with things as they develop around him. A busy mind can slow the body with too much thinking and not enough reacting. While the 22-year-old has been learning the playbook and watching film on his own, he looks to study more tape with D'Alessandris in the room, hoping the coach's presence will expedite the learning process. "If I had a grade, I'm still a C student right now — I'd give myself a C-plus," Fluker said. "But I'm still learning, and each time and each day, my understanding gets a whole lot better. My grade is going up." Fluker's strengths as a three-year starter at Alabama have been his early strengths in San Diego .