Some of the NFL’s top players have yet to take the field in the 2016 season, and it’s looking like a few big names won’t be able to suit up in Week 2. Both Tony Romo and Rob Gronkowski sat out Week 1, and it’s uncertain when they will return.

The Dallas Cowboys were considered the favorites in the NFC East during training camp, but an injury to Romo put the team’s playoff chances in doubt. The quarterback broke a bone in his back in Dallas’ Week 3 preseason game against the Seattle Seahawks, putting him on the shelf for an estimated six to 10 weeks.

After a terrific preseason, Dak Prescott was named Romo’s replacement. He was less than stellar in the Cowboys’ season-opening loss to the New York Giants, leading the team on just one touchdown drive.

Speaking with ESPN on Thursday, Dallas owner Jerry Jones indicated that Prescott could have an extended run as the starting quarterback.

“Nobody knows when his return will be,” Jones said, regarding Romo.

The Cowboys have a bye in Week 7, and the best case scenario might be a return for Romo on Oct. 30 against the Philadelphia Eagles. If he misses 10 weeks, Romo won't make his 2016 debut until Nov. 20 against the Baltimore Ravens.

Rob Gronkowski Patriots Rob Gronkowski watches during pregame drills before a preseason game against the New Orleans Saints at Gillette Stadium on Aug. 11. He might be forced to sit out a second straight regular-season game. Photo: Getty

The New England Patriots have known for some time that they’d be without their starting quarterback for the early part of the season as Tom Brady serves a four-game suspension for his role in Deflategate. What they didn’t know a few weeks ago was that tight end Rob Gronkowski would be dealing with an injury.

Arguably the best offensive weapon in the NFL, Gronkowski missed Week 1 with a hamstring injury. He returned to practice on Wednesday, though that doesn’t mean he’ll be on the field for the team’s home opener against the Miami Dolphins in Week 2. Gronkowski was limited in practice on Thursday, and he didn’t run routes with the rest of the team’s wide receivers and tight ends.

Head coach Bill Belichick hasn’t said whether Gronkowski will play, and the team is likely to err on the side of caution when it comes to the All-Pro. The Patriots opened the season on the road, defeating the Arizona Cardinals without Gronkowski in the lineup.

Missing time is nothing new for Romo and Gronkowski. Romo hasn’t played 16 games since 2012, and Gronkowski last played a full season in 2011.