Cam Newton continues to fight the injury bug, but this time his shoulder is not involved. After Newton was sacked by Adam Butler on a 3rd-and-10 play, the Panthers franchise quarterback left Thursday's preseason game against the New England Patriots with a left foot injury and did not return. 

Here was the play that caused Newton to exit the game:

Newton was seen in a walking boot leaving the game, but according to NFL Network's Ian Rapoport, the injury doesn't appear to be serious and the walking boot was just a precaution. 

The injury is just the latest setback for Newton over the last two seasons. Newton's shoulder issues derailed the Panthers' promising start in 2018 as the team started 6-2 but lost seven-straight games to miss the playoffs. Newton completed 67.9 percent of his passes for 3,395 yards, 24 touchdowns and 13 interceptions for a 94.2 passer rating. He also rushed for 488 yards and four touchdowns on the bad shoulder, which lingered throughout the season. 

The surgery on the shoulder was Newton's second in two years. He underwent surgery on a partially torn rotator cuff in 2017. Carolina has been taking things easy with Newton and his shoulder in training camp, as the Panthers quarterback is working on a new throwing motion to prevent the shoulder problems from reoccurring. 

The Panthers No. 2 quarterback on the depth chart is Kyle Allen. The 2018 undrafted free agent completed 20 of 31 passes for 266 yards in two games (one start). Third-round pick Will Grier is the No. 3 quarterback.