Welcome to the NFL, DeMarco Murray. The rookie ran for a franchise-record 253 rushing yards against St. Louis even though he didn't start, giving coach Jason Garrett a spark to an offense that was nearing one-dimensional status.
But that spark hasn't lasted.
As the Cowboys enter a Sunday night game against the New York Giants with all sorts of playoff implications, the running game needs more electricity.
Enter Tony Fiammetta.
The Cowboys are tied for 14th in the NFL at 114.8 rushing yards per game, but it's been a bigger struggle the past three games.
"I think at different times, it's been better than at other times," Garrett said. "What we want to do is be a balanced offense and we've talked about that a lot here, and at times we've been very good at that and sometimes you go into ballgames and teams are going to say, 'You're not running the football.'"
Garrett has seen his rushing attack fail to reach 100 yards the past three weeks. In that span, Murray has five carries for negative yards and zero carries of 10 or more yards. He also has eight carries for no gain.
Defenses are loading the line of scrimmage with eight defenders to stop Murray and force the Cowboys to become more of a passing team.
One key to the rushing game is Fiammetta, the talented fullback who is returning after missing three games with an inner-ear infection, which affected his balance.
In the three games Murray started while Fiammetta was his fullback, he had four negative plays and 13 carries of 10 or more yards, including five carries of 20 or more. What's also telling is the Cowboys had no carries that went for no gain.
This is not to say Fiammetta is the end-all, be-all to the Cowboys' rushing attack, because tight end John Phillips performed nicely for him the past three weeks.
But it is clear the Cowboys missed Fiammetta.
Fiammetta and Phillips have different styles, which causes some issues for Murray.
Fiammetta is a better blocker and can move defenders out of the way because he has a low center of gravity. That lets Murray hit the hole more smoothly.
Phillips is good at holding up his defender, but this forces Murray to take an extra step or two to find the hole or avoid a potential defender in the second level.
One or two steps can be the difference between a 5-yard gain and a 10-yard gain.
The Cowboys are pleased with Murray because he makes it easier for Garrett to call run plays and to set up the play-action pass, which freezes linebackers into thinking a run play is coming.
In the past three weeks, defenses have been using run blitzes against the Cowboys. Arizona did it frequently Sunday and forced Murray into two negative runs, one carry for zero yards and one carry for 1 yard. Murray managed only 38 yards on 12 carries, his lowest output as a starter.
"One of the things we believe in is we have to be able to move the ball different ways and attack things different ways," Garrett said. "Some of those games where [the defense] said, 'You ain't running it, we're putting eight, nine guys on the line of scrimmage,' and we've been very successful throwing the football. Ideally, you want to have balance each and every week and sometimes that doesn't happen."
Sunday's opponent, the New York Giants, ranks 23rd against the run and is tied for first by allowing five touchdown runs of 10 or more yards. The Giants have given up 39 runs of 10 or more yards, 14th most in the NFL.
The Giants' run defense problems and Fiammetta's return could help solve some of the Cowboy's issues.
It's something Garrett is hoping for.
Calvin Watkins covers the Cowboys for ESPNDallas.com.