In a surprising move just eight days before the season opener, Seahawks offensive line coach Alex Gibbs has resigned.

Adam Schefter of ESPN reports that Gibbs’ resignation was abrupt, and it’s not quite clear why he did it.

However, Schefter notes that some think Gibbs may have resigned as a response to some of Seattle’s recent roster moves. It’s also possible that Gibbs, who announced his retirement in 2007 only to return to coaching in 2008, feels burned out.

But whatever the reasons, just eight months after Pete Carroll called hiring Gibbs an “outstanding achievement,” Carroll now needs to find a competent replacement.