EDEN PRAIRIE, Minn. (AP) — Minnesota Vikings center John Sullivan is still recovering from a back injury.

Sullivan was not on the field Monday for practice, as the Vikings began preparation for their regular-season opener at San Francisco. Coach Mike Zimmer said he's not concerned, but rather encouraged, because Sullivan has been "getting better every day."

Sullivan, the senior member of the offensive line, has been the starter since 2009, his second year in the NFL. He has not missed a game since Oct. 23, 2011, a streak of 58 straight starts including one in the playoffs.

Sullivan has not taken part in practice since Aug. 18. Joe Berger has been filling in, leaving the Vikings without their top backup.

Vikings sign former Patriots DE Zach Moore to practice squad

EDEN PRAIRIE, Minn. (AP) — The Minnesota Vikings have filled out their practice squad with former New England defensive end Zach Moore, a local small college product.

Moore was signed Monday. The Patriots released him Saturday.

Drafted in the sixth round from Concordia University, the NCAA Division II program in St. Paul, Minnesota, Moore appeared in eight games as a rookie last season with the Super Bowl champions. He was inactive in the playoffs.

Wide receiver Isaac Fruechte, a former Gophers player from Caledonia, Minnesota, was given a spot on the practice squad with defensive end B.J. DuBose, offensive lineman Isame Faciane, safety Anthony Harris, linebacker Brian Peters, fullback Blake Renaud, linebacker Brandon Watts, running back Dominique Williams and offensive lineman David Yankey.