Derrick Barnes' participation in the Detroit Lions' training camp was delayed by a hamstring injury that forced him to take treatment and work out on the sideline on his own during practice.
It was exactly how Barnes did not want to start training camp, but he made the best of it.
He kept up with the mental part of the game, and benefitted from advice from Chris Spielman, one of the Lions' all-time great linebackers and a special assistant to team president Rod Wood and principal franchise owner Sheila Ford Hamp.
That didn't make it any easier to be on the outside during practice when he wanted to be inside mixing it up.
"It was upsetting to me, but I knew I had to get my body back in shape before I could come back out here on the field," Barnes said after Wednesday's practice.
"Just being safe. Even though I'm not hurt any more, I make sure I get there early in the morning to get treatment to make sure it didn't happen again."
Barnes is healthy and has been practicing at inside linebacker long enough to play in the Lions' opening preseason game against the Buffalo Bills at Ford Field.
For Barnes, playing Friday is a reward for doing the work to get his body healthy and keeping his mind in the game while watching practice from the sidelines.
"It's very exciting to me," he said. "You worked your whole life to get to this point," he said. "Watching those guys on TV as a young child – the fact that in two days I get to do that and live my dream, it's very exciting. It's amazing. I'm going to make the best of it.
"You're going to be nervous, your first NFL game. Everyone's good. You have to give your all. It's very exciting. I can't wait."
Barnes could have a significant role in the Lions' defense. The scouts and coaches were high on him based on his performance as a starter at Purdue. He was a four-year player. He played rush end until moving to middle linebacker his senior year.
Missing the first part of training camp was a temporary setback for Barnes. He was back in time to take part in Tuesday's padded practice.
Barnes was diligent while unable to practice in keeping up with the mental part of the game.
He prepared and studied as if he were getting ready for practice and participated mentally in practice as if he was running the defense.
"Mental reps are key," he said. "On the sidelines, I stand next to the coaches. Whoever's out there, I put myself in that position. I make the calls from the sideline."
View photos from practice at Detroit Lions Training Camp presented by Rocket Mortgage on Wednesday August 11, 2021.
Spielman has been a mentor to Barnes. He has passed along what he learned – and put into practice -- in the 10 seasons he played inside linebacker in the NFL. The first eight were with the Lions.
"All linebackers, we'd be a fool not to take his advice," Barnes said. "A guy who played the game a long time. A guy who knows the game. You just take that in.
"Playing hard .... knowing what to do is important. Chris always tells you, there's a guy who runs a 4.5 (40-yard dash) but plays at a 4.8. He doesn't know what he's doing. He plays slow. A guy who runs a 4.8 and plays at 4.5 knows exactly what he's doing.
"Just know what you're doing."