Kirk Cousins was oozing with offseason confidence. Working with the Washington Redskins‘ No. 1 offense for organized team activities as Robert Griffin III rehabbed his injured right knee, the second-year quarterback looked the part of the starter. All the way down to the haircut. “Yeah, I found a place in Ashburn to get my haircut, so it was a productive offseason,” he said. After making cameo appearances as Griffin dealt with injuries in 2012, Cousins‘ productive offseason is just getting started. Given what Griffin showed he’s able to do in May, RG3 could be No. 1 by the start of training camp in two months. But for now, Cousins has the chance to prepare like he’ll be the guy for the Redskins next season. “Even if Robert comes backs tomorrow ready to go, the fact that I got reps with the No. 1 offense for the first three practices is a great benefit to me,” Cousins said Thursday. “I view this opportunity as a backup and the challenges it brings as the proving grounds for being a starter.” Cousins’ proving ground at Redskins Park was shared with Rex Grossman and Pat White, but there’s no doubt the Michigan State product would be under center with the starters at the beginning of training camp if Griffin isn’t quite ready to go. Second in line isn’t where he wants to be his entire NFL career, but the 24-year-old is relishing an unexpected chance to show himself. Last season, Cousins started once (in a Dec. 16 victory at the Cleveland Browns) and appeared in two other regular-season games and the Redskins‘ wild-card playoff game against the Seattle Seahawks. He led the Redskins to a win over the Baltimore Ravens in relief and finished with respectable numbers even though he struggled in the playoff appearance.