Tony Romo, Cowboys, 2015

Romo suffered a broken left collarbone in the second game of the season when he was sacked by Eagles LB Jordan Hicks. The Cowboys beat Philadelphia but lost the next seven games with Brandon Weeden and Matt Cassel as their starting QBs. Romo came back late in the season only to re-break a bone in the shoulder. He missed the final five games, as the Cowboys won only once without him all season. Worth noting: Romo suffered a fracture in his back on the third play of the Cowboys’ preseason opener earlier this month. Owner Jerry Jones said he could be ready for the season opener. Other reports have him out six to 10 weeks.

Carson Palmer, Cardinals, 2014

It’s not always bad news when the QB goes down. Palmer missed three of the first four games and then came back to lead the team to five consecutive wins before tearing an ACL and missing the rest of the season. Behind Drew Stanton and Ryan Lindley the Cardinals finished 11-5 but were bounced in the wild-card round of the playoffs with Lindley at quarterback.

Sam Bradford, Rams, 2014

Bradford was coming off an injury-plagued 2013 season, and the Rams showed faith in him by keeping him in the starting QB role. But in the third preseason game, Bradford was sacked and tore the same ACL that limited him the previous season. Shaun Hill — yes, THAT Shaun Hill — took over. However, in Week 2, Hill lost the job to Austin Davis, only to regain it in late November. Hill threw eight TDs and seven interceptions in the Rams’ 6-10 season.

Peyton Manning, Colts, 2011

Manning had neck surgery on May 23 but was not allowed to use the Colts’ facilities — or their medical staff — because of the NFL lockout. By early September, after an MRI, he was told he needed more surgery — a spinal fusion that could end his career. He was ruled out for the season a few days before opening day. Just two years after Manning led the team to the Super Bowl, the Colts finished 2-14 behind QBs Dan Orlovsky and Curtis Painter. That was followed by the firing of coach Jim Caldwell and General Manager Chris Polian, releasing Manning and drafting Andrew Luck first overall.

Romo, 2010

The Cowboys started the season 1-4 when Romo broke a collarbone against the Giants. The Cowboys lost that game and fell to 1-7 before Jerry Jones fired Wade Phillips. Jon Kitna took over at QB, and the Cowboys rallied for a 6-10 season.

Tom Brady, Patriots, 2008

One year after the Patriots had a perfect (16-0) regular season, the Chiefs’ Bernard Pollard landed a blow on Brady’s knee in the season opener. Brady was done for the year. Matt Cassel stepped in and led the Patriots to an 11-5 record. But they missed the playoffs.

Trent Green, Rams, 1999

Green had a breakout season in 1998 for the Redskins before signing a lucrative free-agent deal with the Rams. But in the third preseason game, disaster struck. Green tore ligaments in a knee. A headline in the St. Louis Post-Dispatch the next day read: “Inexperienced Warner will step in as starter.’’ That would be Kurt Warner, who led the Rams to a Super Bowl victory and is considered a likely Pro Football Hall of Fame inductee.