SAN DIEGO -- Ryan Mathews had a busy first day on the job.
The running back, selected 12th overall by the San Diego Chargers in the NFL draft, was the focal point of the team's rookie orientation, which started Friday and includes four sessions through Saturday afternoon.
Mathews was already the workhorse the Chargers expect him to be during the regular season, their first without LaDainian Tomlinson since 2000. He took a lot of reps during his first official practice as a Charger, and admits that everything didn't come easy.
"I knew it was going to be fast paced and I knew there was going to be a lot of reps and mental work," Mathews said. "It's hard work and it's going to take some getting used to, but it's all part of the process. I'm going to take as much as I can from these sessions and use it to prepare for minicamp and the rest of the offseason."
The former Fresno State star was the center of attention for the coaching staff, general manager A.J. Smith and a group of veteran offensive linemen watching intently from the sideline.
"There were some interested guys watching the session," coach Norv Turner said. "All those linemen wanted to come out and see Ryan."
Mathews wore a No. 24 jersey, which will be his number this season. He wore No. 21 at Fresno State as homage to Tomlinson, but that number wasn't available.
"Coach Turner gave me a sheet of available numbers, and No. 24 was close to No. 21," Mathews said. "That was important, and I thought it looked good."