Sam Bradford looked youthful as he strolled to a press conference podium at the Cardinals' practice facility on Wednesday afternoon.

The veteran quarterback – who is only 30, after all, despite his years in the league -- had a freshly shorn haircut and wore an amenable smile.

As the regular season approaches, he has good reason to flash those pearly whites.

Bradford suffered through another knee ailment with the Vikings last year – one that robbed him of all but six quarters on the field – and in the midst of it, he questioned whether his playing career might be over.

The Cardinals gave him that answer, signing Bradford in free agency and keeping him locked in as the starter after selecting Josh Rosen with the No. 10 overall pick in the draft. Bradford will make his debut on Sunday afternoon against the Redskins, hoping to revitalize his career while also appreciating that he made it back at all.

"At this point," Bradford said, "you just realize how special each game is."

Bradford has experienced some of the highest highs in football, winning the Heisman Trophy and becoming the No. 1 overall pick in the draft. He has also dealt with the lowest of the lows, missing the majority of three seasons because of knee injuries, including a pair of torn ACLs.

The Cardinals were abundantly cautious with him early, as Bradford was more observer than active participant in offseason work. The activity level increased in training camp and he made it through the preseason unscathed.

"I know that right now (the knee) does feel as good as it's felt in a long time," Bradford said. "I've done everything in my power to put myself in this position. If something happens and I get injured, or if something happens and it doesn't hold up, I'm going to hold my head high knowing that I put my body and myself in the best position to succeed. I think that's all you can do."

Bradford has not reached his potential in the NFL because of injuries, but the natural talent is still evident. Practice squad quarterback Charles Kanoff said Bradford would go entire days this offseason without throwing an incomplete pass. 

While Bradford only played one full game last season, it was enough to capture Washington coach Jay Gruden's attention. Bradford threw for 346 yards and three touchdowns in Minnesota's season-opening win over the Saints.

"If you protect Sam Bradford and you give him time to throw, he's as good as anybody, really," Gruden said Wednesday in a conference call with Arizona reporters.

The Cardinals have designed an offense that allows Bradford to get the ball out of his hand quickly. When he does need more time, the offensive line must keep him upright.

"We're the only position where our responsibility is to keep another human being healthy," guard Justin Pugh said. "We're looking forward to going out there and doing our job and protecting Sam, as well as all the other guys that are out there."

Bradford showed off his arm talent in the preseason and in training camp, finding wide receivers with precision. While the injury concern is well founded, coach Steve Wilks is feeling optimistic about his quarterback.

"He's at a great place right now," Wilks said.

Bradford is his ninth season, and with a career passer rating of 85.1, maybe he's a finished product. Then again, maybe there is more.

Bradford set a single-season completion record in 2016 with the Vikings and seemed at ease during training camp in yet another new offense. Like everyone else in the locker room, Pugh would love to see what Bradford is capable of with a full year of health.

"He's a guy that's been through a lot of trials and tribulations," Pugh said. "You always cheer for those guys to come back and play well. Let's get Sam to come back and show everyone how talented and how good of a player he is. I would love to be a part of that ride. We're looking forward to doing that with him."