PROVO — It's a long way from Mozambique to Provo.And it's a long way from missionary service to defending against the reigning Heisman Trophy winner and his stable of big-play wide receivers.But that's the challenge facing BYU cornerback Robbie Buckner, who returned from his Mormon mission to the African nation of Mozambique in February. He could be in the starting lineup on Sept. 5 against Oklahoma and quarterback Sam Bradford. It will mark Buckner's first collegiate game."I'm feeling good but trying to shake a little bit of the rust off," said the 5-foot-10, 165-pound redshirt freshman. "It's coming slowly, and I'm doing better with technique every day. I've got a long ways to go after two years and not backpedaling."Buckner smiled. "I spent two years chasing down little African kids," he added. "That helped me out."Buckner is one of several candidates vying for the starting field corner spot, along with a trio of junior college transfers — Brian Logan (5-9, 195), Lee Aguirre (5-9, 200) and Corby Eason (5-10, 180).BYU coach Bronco Mendenhall said the influx of new faces in the defensive secondary has given the defense a considerable upgrade in speed, talent and depth.On the other hand, the Cougars are short on experience at that position. Junior Brandon Bradley appears to have the other cornerback spot locked up, but he is being held out of practice due to a sore knee."The good news is, we have more corners than probably we've had since I've been the coach in terms of competition," Mendenhall said. "Eventually, that will play out once the junior college players learn what to do."Buckner, who sustained a minor hamstring injury in practice on Wednesday, is the only one of the group of new corners who has previously been in the program. After making a solid impression during fall camp in 2006, he redshirted, then left for his mission. Buckner, an Ashdown, Ark., native, said that having been at BYU for a year gives him a bit of an advantage over his competitors."There are a lot of new guys and it helps me that I've been here," he said.His approach is rooted in simply putting forth maximum effort. "I try to get the coaches to notice my work ethic," Buckner said. "If you mess up and you're going hard, it's not that bad. I just try to keep working hard."While Buckner did not participate in spring drills, he spent considerable time on campus during the summer preparing for this season. In the process, he earned the respect of his teammates. Based on his performance in off-season workouts, which coaches aren't allowed to watch, Cougar seniors voted Buckner a starter on the pre-fall camp depth chart."Robbie's made a strong impression on our team," Mendenhall said. "He works so hard and is so reliable and so diligent and so tough. I don't think he intends to give up the (starting) spot.""Robbie Buckner has been awesome," said defensive lineman Jan Jorgensen. "He's making plays out there. I think the one question mark that we've had on the defense is, who's going to play that corner on the other side of Brandon Bradley? Robbie looks great. He's a hard worker. Hopefully, he'll keep that up."Buckner said his mission prepared him for difficult times, on and off the field."My mission was great," he said. "I heard it was the hardest mission in the world. But the people are great, and I fell in love with them. It was a great experience for me."During the first year of his mission, Buckner admitted he didn't exercise much."Then, about six months left, it hit me that I was going to have to go back and play Division I football," he said. "In my last area, there was a gym. My companion and I would get up at 5 o'clock in the morning and go to the gym. I gained a little bit of strength, but I gained a whole lot when I got back here."Aside from the fact that Sept. 5 will mark his first college game, Buckner is looking forward to playing it in Dallas, which is about a three-hour drive from his hometown in Arkansas."It will be a challenge," he said. "I'm ready for that game, to see family and friends there."In the meantime, Buckner said he's already seen plenty of BYU vs. Oklahoma — while playing the NCAA Football 2010 video game.What's the outcome?Buckner laughed. "I always win," he said.The real competition will be here soon enough.