So do the New York Giants in an opener between NFC East rivals.
''When Murray was back there, you kind of understood what type of runner he was,'' New York defensive end Cullen Jenkins said. ''You prepare for it for most of the game. Now, you know, they've got a lot of choices and a lot of different backs, different styles that they can throw at you.''
Those are the two running backs likely to see the most work against the Giants on Sunday night since Christine Michael probably won't be ready just a week after coming over in a trade from Seattle.
Murray broke all-time NFL rushing leader Emmitt Smith's franchise record with 1,845 yards last season, easing the load on Romo as the Cowboys won the division. Dallas beat Detroit in a wild-card game before losing to Green Bay in the divisional round of the playoffs.
The preseason did little to settle how Dallas will fill the void, but that didn't seem to bother coach Jason Garrett. He's not even interested in sharing who will be lined up behind Romo for Dallas' first offensive snap.
''It doesn't matter,'' Garrett said. ''The only thing that matters is everybody getting ready to play and if their number is called up they go out there and be their best.''
The Giants have a big hole to fill, too, and don't know for how long. After rejoining his team a week before the opener, star pass rusher Jason Pierre-Paul returned home to South Florida to continue his recovery from a fireworks accident that damaged his right hand.
Coach Tom Coughlin says he doesn't know when Pierre-Paul will be able to practice.
''`Disappointed' would be a word that's down the line a little bit more,'' Coughlin said. ''I'm actually still very concerned about him. But he seems to be doing an outstanding job of bouncing back and I know he is trying to put this all behind him and return to the player that he was.''
If the Giants have to outscore the Cowboys, Eli Manning is visiting a stadium where he's done that before. Going into his 11th straight opener, Manning has averaged 321 yards passing and more than three touchdowns in six games at the $1.2 billion home of the Cowboys.
That included the first regular-season game there in 2009, a 33-31 New York win that he commemorated by writing on a wall in the locker room.
''I guess good weather, I don't know,'' he joked, perhaps aware that the stadium's retractable roof has been open for half of his starts there. ''Hopefully we can have another day being productive throwing the ball. We're going to need to.''
Things to consider going into the 18th meeting between Romo and Manning, including the day Romo became the Dallas starter when replaced Drew Bledsoe at halftime of a 36-22 New York win in 2006.
THE CATCH REVISITED: It's the first meeting between Odell Beckham Jr. and Brandon Carr since the Giants receiver's remarkable one-handed catch over the Dallas cornerback overshadowed a 31-28 victory by the Cowboys that completed their second straight season sweep.
SUSPENDED COWBOYS: It's the first of four games that the Dallas defense will be without defensive end Greg Hardy (domestic violence case) and linebacker Rolando McClain (substance abuse violation). It's also an opportunity for young Cowboys pass rushers DeMarcus Lawrence and Randy Gregory, who will make his NFL debut.
EARLY SPOTLIGHT: Giants rookie left tackle Ereck Flowers will be protecting Manning's blind side in his debut with Will Beatty sidelined by a pectoral injury. He was the ninth overall pick in the draft, the highest for New York since 2004.
WELCOME BACK: Dallas linebacker Sean Lee makes his first regular-season appearance since Dec. 9, 2013, at Chicago. He missed all of last season after tearing the anterior cruciate ligament in his left knee in the first offseason practice.
FAMILIAR FACES: Receiver-kick returner Dwayne Harris and defensive end George Selvie are facing their former team after signing with the Giants in the offseason. New York also added linebacker Jasper Brinkley, who was cut by the Cowboys at the end of the preseason after signing in March.
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