OAKLAND -- Assistant offensive line coach Steve Wisniewski resigned his position due to personal reasons, the Raiders announced Thursday.
Wisniewski was retained on coach Dennis Allen's staff to work with line coach Frank Pollack as the team shifted its philosophy to be a strictly zone blocking team.
The club's release said Wisniewski would continue to assist the Raiders as an "ambassador." Wisniewski, who was hired as former line coach Bob Wylie's assistant in 2011 on Hue Jackson's staff, was not available for comment.
The Raiders, according to the release, will not fill Wisniewski's position, leaving Pollack as one of eight NFL offensive line coaches without an assistant.
Players begin reporting to training camp in Napa on Saturday and Sunday, with the first practice Monday morning.
Wisniewski's nephew, Steffen, started at left guard as a rookie in 2011 and is slated to be the starting center this season.
An eight-time Pro Bowl selection, Wisniewski played for the Raiders from 1989 through 2001. He became a minister at pastor Napoleon Kaufman's, "The Well Christian Community" in Dublin and is still listed as a minister on the church's website.
Wisniewski was an occasional visitor to Raiders' training camp until got back into football in 2010, working on Jim Harbaugh's staff at Stanford as a strength and conditioning assistant.
According to the camp schedule, the practices run from 2:20 p.m.-5:10 p.m. each day.
Since the Raiders began training in Napa in 1996, practices have been closed to the general public, although youth groups, season ticket holders, sponsors and advertisers have been invited guests.