Minnesota Vikings coach Mike Zimmer has fired offensive line coach Jeff Davidson following a season of struggles at the position that began with two veteran starters landing on injured reserve.

Zimmer revealed the decision to not renew Davidson’s contract Tuesday when asked if his entire staff would return for 2016.

Zimmer called the offensive line’s performance “sporadic” and said he has “no idea” whether center John Sullivan and right tackle Phil Loadholt can simply step back in to their spots after sitting out the 2015 season with injuries. Zimmer said he anticipates offensive coordinator Norv Turner return.

The Vikings finished with the fourth-fewest yards in the league. They were 16th in scoring.