On Friday at training camp, the Arizona Cardinals had an injury concern with second-year defensive tackle Walter Nolen. He went to the locker room with trainers, looking at his left knee, which was the one he had surgically repaired at the end of last season. It turns out he was okay. After Saturday's off day, Nolen was back on the field at State Farm Stadium on Sunday and practiced as he normaly would. That is huge news for Cardinals fans.Head coach Mike LaFleur was asked about Nolen before Sunday's practice. "Walt's good," he said. "Sometimes you name the player when they've hada serious injury. They feel some type of way about it.There's a process both mentally and physically getting through that, you know, so he's good, which is obviously a good thing forhim, butthe Cardinals as well."Based on that response, it would appear that Nolen felt something that wasn't right, but after further examination, it was more worry than injury. With a lot resting on his shoulders this season when it comes to defensive playmaking up front, getting over this and avoiding further injury will be critical. Get more Cardinals and NFL coverage from Cards Wire's Jess Root and others by listening to the latest on the Rise Up, See Red podcast. Subscribe on Spotify,YouTubeorApple Podcasts.This article originally appeared on Cards Wire: Walter Nolen injury: 2nd-year DT back at practice on Sunday