Dallas Cowboys running backs Skip Peete has been relieved of his duties by coach Jason Garrett and will not return for the 2013 season, according to a source.Peete, who had been with the Cowboys since 2007, was informed in a meeting with Garrett Monday.Peete was surprised by the move, given the injuries to running backs DeMarco Murray the past two seasons that limited his effectiveness, and the struggles on the offensive line to open holes for the running game, according to the source.The Cowboys set a team record for fewest rushing yards in a 16-game season in 2012 with just 1,265.Murray rushed for 663 yards, the lowest for a Cowboys leading rusher in 23 years. He missed six games with a sprained foot.Peete never had a 1,000-yard rusher in Dallas, but did produce a Pro Bowler in Marion Barber in 2007. Barber led the team in rushing that season with 975 yards and 10 touchdowns, despite sharing carries with Julius Jones.A disappointed Garrett hinted at changes with the running game in his news conference after the season-ending loss at Washington.We have to do a better job running the football, Garrett said. DeMarco Murray was out for a large portion of this season, but having said that, you have to put the next guy in there and you have to be effective running it.It just helps your football team. It helps your offensive line, it helps your quarterback, it helps your defense. Thats something that weve tried to do and we werent as effective as we needed to be.We have to make a commitment to being better next year.Peete is the first change, but he might not be the only staff move in 2013.Special teams coach Joe DeCamillis interviewed for the Chicago Bears head coaching job on Saturday. Even if he doesnt get the Bears job, he could be in line for a lateral move to another team. The Cowboys blocked a potential move by DeCamillis to the Oakland Raiders last season. Will they do the same if given a similar option in 2013?The Cowboys have yet to rule on the future of defensive coordinator Rob Ryan. Garrett and Jones refused to guarantee his return during interviews last week, saying they were not ready to discuss personnel.Cowboys sign eightWide receiver Anthony Armstrong is back with the Cowboys.Armstrong was one of eight players signed to the Cowboys reserve/future list on Monday.He joins tight end Colin Cochart, guard Ray Dominguez, wide receiver Jared Green, long snapper Charley Hughlett, wide receiver Carlton Mitchell, linebacker Cameron Sheffield, tackle Aderious Simmons and cornerback Brandon Underwood.Armstrong, who attended Carrollton Smith High School and West Texas A&M, signed with Dallas on Nov. 26 and played in one game, against Pittsburgh. He was released on Dec. 22.