A ragged season for the Arizona Cardinals took another devastating turn in London.

Quarterback Carson Palmer will have surgery on a broken left arm suffered Sunday and will likely miss eight weeks, coach Bruce Arians announced. Palmer exited during the Cardinals' 33-0 loss to the Rams late in the second quarter with the injury and was replaced by Drew Stanton.

This could potentially be the end of an era in Arizona. Palmer openly debated his football future this offseason before deciding to play another season. Arians' future and whether wide receiver Larry Fitzgerald keeps playing figure to become bigger storylines in the coming weeks.

Now 3-4, the Cardinals face a difficult path to relevance because of their offensive inefficiencies. The offense lost running back David Johnson, its best player, early in the year. The addition of another aging veteran Adrian Peterson gave the team a boost last week against the Buccaneers, but ultimately this is a team lucky to have three wins. (They barely beat the Colts and 49ers.) Trailing 20-0 before Stanton entered the game Sunday, the Cardinals have not been competitive multiple times this year. That trend figures to continue.

After Palmer left with his arm injury, Stanton sprayed passes and did not look comfortable in the pocket. (He completed 5 of 14 passes for only 64 yards with an interception and a fumble.) The Cardinals' offensive line didn't give Palmer or Stanton a chance and Peterson found little room to run, finishing with 21 yards on 11 carries.

Palmer was throwing the ball better than people believe this season, but the team's lack of pass protection and erratic running game has limited the Cardinals' offense (Palmer entered Sunday third in passing yards and tenth in yards-per-attempt). But the struggling line and poor running game showed up again in London, where the Rams started to get consistent pressure on him in the second quarter. The injury came on a play where the Cardinals atypically left seven men in to block a Rams blitz. The pressure still got to Palmer, with Rams linebacker Alec Ogletree delivering the decisive blow.

The eight-week timeline gives Palmer a chance to return this season and perhaps play again before the end of his 14-year career. But it's hard not to envision this injury as the coda to an entertaining run for Palmer, Arians and Fitzgerald in the desert.