OFFSEASON EVALUATION: Jason Garrett and the Dallas Cowboys offense continues to evolve

Jason Garrett likes where the Cowboys are offensively, but he also thinks they can be even better.

The Dallas Cowboys coach said they have evaluated the offense over the past six seasons since he arrived in Dallas as offensive coordinator. The past six seasons combined, the Cowboys rank fourth in total offense (370.7 yards per game), seventh in scoring (24.1), fourth in passing (262.0) and 22nd in rushing (108.6).

“You look at those things, and you say, ‘Boy, a lot of that stuff is pretty good,'” Garrett said. “You say, ‘OK, we want to build on that stuff. We want to continue down that track with our offensive football team.'”

Garrett, however, will give up play-calling duties for 2013. Offensive line coach Bill Callahan likely will take over that role. The Cowboys made four changes to their offensive coaching staff, with Wes Phillips moving from assistant line coach to tight ends coach, newcomer Frank Pollack taking over as assistant offensive line coach, Derek Dooley being hired as receivers coach and Gary Brown coming in as running backs coach.

The Cowboys will see some changes in personnel, too, though maybe not many with Felix Jones, Kevin Ogletree and John Phillips as the only unrestricted free agents on offense. None of those three is a starter. Center Phil Costa is a restricted free agent. Dallas again might be looking to shore up its offensive line after adding a pair of free agent guards in Nate Livings and Mackenzy Bernadeau last off-season.

“This is an opportunity to add some people, add some influence to our offense,” Garrett said, “and hopefully it’s a tweak for us that can help us get a little bit better and help us break through as a football team. So that’s really the approach right now. We want to stay on the same track, but also we want to add coaches to our staff that can really help us break through.”

Despite being one of the league’s best offenses, the Cowboys are 55-41 over the past six years with only two playoff berths. They are 1-2 in postseason games in that stretch.