One of the more curious subplots involving the Detroit Lions defense this season was the case of linebacker Tahir Whitehead.
After starting at the SAM linebacker spot to begin the 2014 season, he moved over to the MIKE spot Week 3 when Stephen Tulloch tore the ACL in his left knee. He played terrific there all year there. He was the team's second-leading tackler behind DeAndre Levy in 2014 and helped the defense rank second overall.
But after a slow training camp and an unproductive preseason, Whitehead lost his starting spot to begin the 2015 season.
In fact, he wasn't a big part of the defense at all as the Lions floundered to a 1-7 record to begin the year.
Whitehead played just 32 percent of the snaps on defense the first eight weeks. He never got over 50 percent in any single game.
"Early in the year he wasn't making the plays and he'd be the first to tell you that," defensive coordinator Teryl Austin said.
Whitehead sees it a little different, however.
"It was just a matter of opportunity," he said earlier this week as he cleaned out his locker with the rest of his teammates. "Early on, you can't make plays when you're not on the field.
"That's what people fail to realize. They say I wasn't quite playing well, but it's not the matter that I wasn't playing well, it was the matter of I wasn't really on the field that much.
"If I'm getting 10 plays in the game, and I'm playing man-to-man in coverage and they're not throwing it to my man, of course it's going to look like I'm not really doing much. So, that's what it really boiled down to and what was the difference early on, I wasn't quite getting the snap count I was getting at the end."
After the team's bye week, Whitehead became a starter again and saw a dramatic increase in his snaps. And wouldn't you know it, the Lions defense began playing a lot better too.
Whitehead only had one game where he played less than 73 percent of the snaps over the final eight games of the season. He finished the last two months playing in 81 percent of the snaps on defense.
He had a huge impact on the win in Chicago Week 17, recording six tackles, two tackles for loss and a late second-quarter interception that led to a Matt Prater franchise record 59-yard field goal to give the Lions a 10-0 lead at the half.
"When given the opportunity, I can make the best of it," Whitehead said. "I can take advantage of it and know that I'm a good player. That's more-so what I wanted to show and I believe I did a good job stating that case."
Whitehead, a former fifth-round pick by the Lions in 2012, is an unrestricted free agent this offseason.
Austin praised his versatility the second half of the season, in that he can play both on the outside and interior. Whitehead says he'd love to re-sign with Detroit, but sees himself as a MIKE moving forward.
"When I look at it, me personally, I see myself as a MIKE," he said. "To be able to utilize my speed and being able to play sideline to sideline.
"Never really playing MIKE prior to last year (2014), I've grown to really like the position and get comfortable there. I see myself as a MIKE backer."
The Lions will have to decide on the future of their current starting MIKE linebacker, Stephen Tulloch, who turned into a part-time player this season. Tulloch is due to make $5.5 million in base salary with a $500,000 roster bonus and count $7.3 million on next year's cap.
Whitehead could be a nice option in the middle.
"I'd like to be back here," Whitehead said. "But as I stated earlier, I just have to sit back and wait and let everything play out, because there's a lot of unknowns right now."