When the Dallas Cowboys began practice preparations Wednesday for their Week 5 home game against the Cincinnati Bengals, multiple offensive linemen and star wide receiver Dez Bryant were in the trainer's room and safety Jeff Heath was handling the place-kicking chores.

Still, the mood is upbeat in Dallas.

"Doing great," Cowboys head coach Jason Garrett said.

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As in recent years, injuries are hitting the Cowboys (3-1) at key positions early in the season. Already without quarterback Tony Romo (back) and left guard La'el Collins (toe), Dallas is confident left tackle Tyron Smith (back) and top reserve Chaz Green (foot) will be back but there was less certainty for Bryant (knee) and cornerback Orlando Scandrick (hamstrings) playing this week.

"He's just a complete receiver," said Bengals cornerback Adam Jones of Bryant, his workout partner in New Orleans in the offseason. "He's physical, he can run, he goes up and gets the ball at the highest point. And he plays with big swag - that's what makes him so good."

Bryant missed Week 4 with a fracture below his right knee but Cowboys owner Jerry Jones said Tuesday not to rule him out this week.

Sixth-round pick Anthony Brown has filled in for Scandrick, who missed last season with a knee injury.

Scandrick could be invaluable against the Bengals and wide receiver A.J. Green, who has 32 receptions for 468 yards and two touchdowns in 2016. Green caught 10 of quarterback Andy Dalton's 22 completions in Week 4 against the Miami Dolphins, and had a 12-catch, 180-yard game in the season opener. He's averaging 14.6 yards per reception.

It might not be Green who most concerns Cowboys defensive coordinator Rod Marinelli, given the traditional gaping hole in his cover-2 defense, one proven repeatedly last season against the Cowboys, is down the seam.

The Bengals were expecting Tyler Eifert to play for the first time this season on Sunday, but a "tweaked back" forced the club to rule out the Pro Bowl tight end. Eifert has been inactive for all four games to date recovering from offseason ankle surgery.

The 26-year-old Eifert, the Bengals' first-round pick in 2013 out of Notre Dame, caught 52 passes for 615 yards and 13 touchdowns last season, a franchise record for TDs by a tight end.

"Some guys can go through a bad run of luck, and I think Tyler has had a bad run of luck," coach Marvin Lewis told reporters Friday. "He's conscientious about his body, conscientious about being a pro, and you love that part about him. That's what Coach (Brian) Kelly told me right away from Notre Dame.

"People questioned certain things about him coming out (for the NFL draft), and Brian assured me that those were kind of false accusations, or they just weren't totally true, and said he would be everything we wanted, and he's been. I think unfortunately he has had some injuries that have kept him out of playing. But he'll overcome them."

The Bengals will again rely on second-year tight end C.J. Uzomah in Eifert's absence. Uzomah has 11 catches for 144 yards and no touchdowns in four games this season.

Cincinnati has come up with only spare change on too many red-zone trips, where offenses make the big money.

On 13 possessions inside the opponent's 20-yard line, Cincinnati has scored only four touchdowns with eight field goals. The Bengals rank 28th in the league in rushing offense at barely 80 yards per game, leaving Dalton somewhat exposed. Dalton has been sacked 13 times, and has checked away from running plays often.

"We're going to do whatever it takes to win," Dalton said. "Some of these weeks, we've been able to throw a lot. Whatever's the best way for us to score. If (passing yards) are up there, so be it. If it's not, it's not."

For the Cowboys, kicker Dan Bailey (back) could be limited all week. Garrett will only make a move to a replacement if the ailment stretches into the weekend. Garrett will not use "double emergency" option Heath in a game unless circumstances force it.

"Longest I've ever hit was 49 yards, that was in high school. I'd be comfortable mid-40s probably," Heath said. "It's just kicking."

Rumblings of Romo's return later this month are far enough in the distance that there should be no distraction for Dallas' rookie backfield combination of quarterback Dak Prescott - interception-free after 131 pass attempts and completing 67.9 percent of his passes - and running back Ezekiel Elliott.

The level-headed Prescott said only "good fortune" has helped him start the season without a pick.

"They have a great, great front seven," said Prescott, who led the Cowboys from behind to win at San Francisco last week. "We know we've got a pretty good stretch coming up starting this Sunday with the Bengals. We're confident, our team, our offense, in the direction we're headed."

Elliott, the fourth overall pick in the draft, was targeted by Cowboys' coaches over an impactful defensive player because, as Garrett put it, he can really help a defense.

That philosophy, copied from a successful 2014 strategy employed with DeMarco Murray as the bell-cow back, is taking hold. Elliott leads the NFL in rushing attempts and rushing yards entering Week 5, and Lewis is taking notice.

"He's everything we thought he would be," Lewis said. "Fast, strong, great vision, great cutter, the ability to make people miss within the hole, speed to the perimeter, runs behind his pads."

The Bengals are talented defensively, with defensive tackle Geno Atkins and left defensive end Carlos Dunlap in front a linebacker corps that once again includes tenacious inside linebacker Vontaze Burfict. Burfict returned to the lineup last week after a three-game suspension for player-safety rules violations.

Not having Bryant at 100 percent could work in Cincinnati's favor because it frees Lewis to play all of his cards: mixing coverages, fronts and rotating personnel. The Bengals are active and mix blitzes from every direction, a challenge to a rookie quarterback even with Prescott's poise and calm.

Winning the line of scrimmage is a challenge Lewis made to his team Wednesday, with the expectation that Dallas would use Elliott and backup running back Alfred Morris to pound the ball until Cincinnati shows it can stop the run.

"Both these runners run through a lot of contact," Lewis said. "So we really have to have our big boy pads on and tackle."