SANTA CLARA – The eldest non-kicker on the 49ers’ roster is learning a new position this offseason.

But Ahmad Brooks has plenty of experience adapting to new positions during his 12-year NFL career. He has played inside linebacker, outside linebacker in a 3-4 and defensive end in pass-rush situations.

Now, Brooks has moved to the strong side linebacker position -- the “Sam” -- in the 49ers’ new 4-3 scheme under first-year defensive coordinator Robert Saleh.

“He’s getting them (first-team repetitions) because he deserves them,” 49ers coach Kyle Shanahan said this week. “Watching how he played last year and then going into this offseason, you never know when a guy who has been around a bunch, if they’re going to feel that they need the offseason like other people do. And Ahmad’s been here every day and he’s needed it just like everyone has anytime you’re learning a new scheme.

“But anytime you have a veteran like that, you worry that, hey, maybe they won’t think that they do need it. But Ahmad has and he’s been here. He’s worked at everything. He’s in good shape. He’s done what we’ve asked in the weight room with Ray and he’s done everything with the position coaches and coordinator on defense. So, I think he’s learning it and he should because he’s putting the work in.”

Brooks, 33, has entered the past three offseasons with his place on the 49ers seemingly in jeopardy. But the 49ers have not been able to find a younger, better player to replace him. Brooks has tied for the team-lead in sacks in each of the past four seasons with 27 sacks over that span.

Eli Harold, Dekoda Watson and undrafted rookie Jimmie Gilbert were the other players who lined up at the Sam position during the first week of 49ers organized team activities.

Brooks and Aaron Lynch, starters at outside linebacker for the 49ers in the previous systems, have the steepest learning curves in the transition to a new defense. Lynch has moved to the team’s pass-rush defensive end position, known as the “Leo.”

“I think techniques are totally different,” Shanahan said. “How you want to take on blocks, how you want to play the run. Ahmad has been around a little longer than Aaron. So he’s probably had a little bit more crossover, some similar schemes.”