Cardinals safety Tyrann Mathieu, after fighting through knee rehab and a thumb injury last season, is ready to rebound in 2015.

Tyrann Mathieu is getting healthy. This Bruce Arians knows and has been counting on as the Cardinals' coach builds his defense for 2015.

After Mathieu had such a special rookie season in 2013 before shredding his knee, Arians seeks more than just health from the safety, and he thinks Mathieu might just have it.

"He's got a gleam in his eye that I haven't seen in a while," Arians said, and to this point, Mathieu completely agrees.

"It's been a long time since I've been healthy," Mathieu said Monday. "Last year I felt like I took a back seat. I played well my rookie year and then last year it was kind of, eh, I was there but I wasn't there. This (year) is more important for me because I really want to let everyone know I'm back and I can still make some plays."

Mathieu ended up playing 13 games last season, starting six. Coming off the devastating knee injury at the end of 2013, Mathieu did little in the first six games of the season before starting to break out. He never reached his rookie level though, and any chance he might have had of getting there by the end of the season was derailed with a broken thumb in Atlanta. It cost him two games and crucial practice time. He finished with just 39 tackles (after 63 as a rookie.)

Mathieu had been both optimistic and realistic about his journey back from a torn ACL and LCL. He talked often all last season about knowing there were difficult days in coming back, especially mentally. Training camp was not easy, slowly getting eased into practice. He was held out of the regular-season opener. His snaps were limited.

The comeback was "was way harder than I thought," Mathieu said, and that doesn't include the frustration of the broken

thumb.

"You saw him fight through it last year," Arians said. "He was not the player he was used to (being) and it was very frustrating for him."

Motivation is apparent. When his comment of letting people know "I can still make some plays" is noted, Mathieu acknowledges he means it.

"You hear people talk and I had time to listen to them talk, so it's like … I hear it," Mathieu said. "Like I said, I didn't feel like I made enough plays last year to help our team. I am looking forward to this year because I know I can do it."

Mathieu's knee is fine, he said. The thumb still isn't quite perfect, but he believes it will be by the team reaches organized team activities, and that the rookie Tyrann Mathieu will return.

He shrugged his shoulders at adjusting to new defensive coordinator James Bettcher or even where he might fit in a safety-saturated secondary. Mathieu knows if he plays as he is capable, there will be a place for him on the field.

"I don't think I've ever really gone into a season where …  I mean, even in college and high school, my position has never really been defined," Mathieu said. "I've kind of been all over the place. For me, it's about competing and showing coach I can play on every down."