GLENDALE, Ariz. -- Remember when the Dallas Cowboys' offense was among the most envied in the NFL?
Nobody had a better offensive line. Running back Ezekiel Elliott led the NFL in rushing. Quarterback Dak Prescott had so many weapons at his disposal -- wide receivers Dez Bryant and Cole Beasley and tight end Jason Witten -- that he could pick apart any defense.
That's all so 2016.
The Cowboys' offense is struggling in 2017.
After finishing as the fifth-ranked offense in terms of yards and points and second in rushing last season, the Cowboys are 16th in points (21.3), 19th in yards (311) and 22nd in rushing (89.3) so far this year.
They need longer drives
Through three games, the Cowboys (2-1) have seven touchdown drives, one fewer than last year through three games. Five of the seven drives have started at midfield or in the opponent's territory. Their longest touchdown drive was the four-play, 75-yard drive in the fourth quarter of Monday's win against the Arizona Cardinals, and it started with a 53-yard completion from Prescott to Brice Butler.
In the first three games last season, seven of the Cowboys' eight touchdown drives were at least nine plays and ranged from 72 to 94 yards.
The Cowboys have converted 13 of 38 third-down chances so far this season (34 percent). They converted 21 of 40 third-down chances in the first three games last year. The Cowboys have gone back-to-back games with fewer than 20 first downs (15 first downs in the win vs. Arizona, and 16 in the Week 2 loss to Denver). The only time they had fewer than 20 first downs in consecutive games last year was in Weeks 13 and 14.
On Monday, the Cowboys needed Prescott to make impromptu plays when things broke down, which is a difficult way to live in the NFL.
"Very few times in the NFL does a quarterback go back and everything is clean and everything is easy and [he has] a nice pocket to throw from," Dallas coach Jason Garrett said. "There's always somebody in your face, you always have to move, you always have to keep your eyes down the field with people around you and make plays. He's capable of doing that from the pocket. He's capable of doing that by running and making things happen, but also just buying some time and getting out in space and keeping his eyes down the field."
Offensive line needs to jell
The Cowboys lost two starters up front from last year. Right tackle Doug Free retired and left guard Ronald Leary left via free agency.
La'el Collins moved from left guard to right tackle. He has had good moments (a key block on Elliott's 8-yard touchdown Monday) and bad moments (as Denver LB Von Miller does with many offensive tackles, he spun Collins around). Chaz Green entered the season with no experience at left guard and has made only the third and fourth starts of his young career.
Replacing 40 percent of the line is significant even if the remaining 60 percent are All-Pros Tyron Smith, Travis Frederick and Zack Martin.
"One of the things you find out is, really, for a long, long time in the NFL, and certainly now, the way you get better, particularly in the running game, is experience during the game," Garrett said. "That's been the case for a long time. You like to think that you become a better running team as the year goes on because you get a chance to run these runs in real life against a real opponent. And hopefully you benefit from those experiences. That's for everybody. That's for a veteran offensive line group. And … when you have a couple of young guys in there, hopefully they're learning from the experiences as we go and we get better."
Lack of fast starts
The Cowboys had eight plays for 33 total yards on their first drive against the Giants in Week 1 and ended up punting. They punted after three plays and nine yards against the Broncos and three yards against the Cardinals.
Last year, with a rookie quarterback and a rookie running back, the Cowboys scored on their first possession in all three games to start the season. They went 70 yards on 15 plays against the Giants and 76 yards on 13 plays against the Redskins, leading to field goals. Against the Bears, a 10-play, 75-yard drive ended with a touchdown.
The Cowboys scored on their first possession in nine games last season.
Facing good defenses
This seems to be the most common explanation for the early-season struggles. The Broncos have the fourth-ranked defense in terms of yards, while the Cardinals are ninth. The Giants check in at No. 16. Last season, the Giants finished 10th, the Redskins were 28th and Bears were 15th.
This season, the Cardinals and Broncos have stacked the box and dared the Cowboys to pass the ball. Elliott had eight yards on nine carries against the Broncos. He had 80 yards on 22 carries against Arizona, but 50 yards came on two plays.
The Cowboys believe the cumulative effect of running the ball will eventually wear down their opponents. It worked better against the Cardinals -- Elliott had 49 yards on 14 carries in the second half, but five of those carries went for two yards or less.
The Los Angeles Rams come to AT&T Stadium on Sunday with the 22nd-ranked defense in terms of yards and 26th in points allowed. Of course, Rams defensive coordinator Wade Phillips will want to have a good showing against the team that fired him as head coach midway through the 2010 season.
"We just got to keep pushing," Bryant said. "It's a process. I said that it's a process. And when it clicks, it's going to click and it's going to be one of the best things you've ever seen on turf."