For the first time in his NFL career, San Francisco 49ers defensive lineman Arik Armstead does not have to learn a new system. He is grateful for the continuity carried over from last year when he first started working with head coach Kyle Shanahan and defensive coordinator Robert Saleh.

"I've had three new coaches in my first three years," Armstead said on Wednesday. "It definitely feels good to be in the same system and not have to relearn a whole new scheme. You get more comfortable in it the second year."

The 49ers picked up Armstead's $9 million fifth-year option, which will keep him with the team through the 2019 season.

"It feels good to be wanted," he said. "I think everybody wants to be wanted. I think they have faith in me, in my ability moving forward, and it feels good to be wanted in this organization. I've loved being here since I got here a couple of years ago. I'm from Northern California so being wanted by this team is great. I think we're building something special here and I want to be a part of it."

How did Armstead find out that his fifth-year option was picked up by the 49ers? While general manager John Lynch discussed the possibility with him during last season, the defensive lineman wasn't privy to any insider information when the move was made.

"I just saw it on the internet like everybody else," Armstead said.

Injuries have plagued Armstead's NFL career. He is coming off a shortened 2017 season that saw him break his hand during a Week 6 matchup against the Washington Redskins. The 49ers placed Armstead on injured reserve on October 17, 2017. His 2016 campaign also ended on injured reserve. Armstead played in just eight games with four starts before a nagging shoulder injury and surgery finished his season.

"I've been hurt two years in a row," Armstead said. "Definitely have a lot to prove and looking forward to having a healthy season. I know what I'm capable of when I'm on the field."

Armstead notices the online criticism regarding his injuries. He even defended himself via Twitter last season when fans questioned his toughness because they wanted to see him play with a cast. It was later revealed that a cast was not an option for Armstead due to the severity of the injury. Even Saleh defended his player.

"If he could have played with a club, he would have played with a club," Saleh said in October. "If he can play with one hand, he'll play with one hand. It's just unfortunate, the injury he had, the location of where it was."

"Of course there's critics and fans want players to be out there and not be hurt, but part of football is being injured," Armstead said on Wednesday. "I can't control that. All I can control is if I do get hurt, trying to rehab, and get back healthy, and play to the best of my ability. Those people don't really understand what's going on so you look at it and you brush it off.

"Just trying to keep that confidence in myself. I have a strong support system, and people who love me and think highly of me. That's all that matters."