Norv Turner stepped down as offensive coordinator of the Minnesota Vikings in a surprising move.

"Forgive me, I haven't slept in days," Turner told NFL.com. "This is the hardest thing I've done in football."

The Vikings began the season 4-0 and then lost two straight games.

"Sometimes, you feel like you might be holding them back," Turner said, "holding them back from things all getting on the same page. I don't want anyone to think I was bailing. It just wasn't working."

Turner clarified a few things. He's completely healthy. He doesn't know if he's retiring at age 64, though he admits moving around has been difficult for his wife. 

A source involved with the situation was adamant that Turner was not forced out by the team. Turner's decision caught Zimmer by surprise.