CHARLOTTE, N.C. -- Quarterback Cam Newton's status is uncertain for Sunday's game at Arizona after he aggravated the sprained left foot injury he suffered in the third preseason game.

Newton informed team officials of the injury after Thursday's 20-14 loss to Tampa Bay that dropped Carolina to 0-2.

He spent Tuesday's practice working inside with the trainer rehabbing the injury while backup Kyle Allen and third-round pick Will Grier took all the snaps.

General manager Marty Hurney was asked before practice about the level of concern for Newton being ready for the Cardinals. He said that the situation was day-to-day.

Newton didn't blame the Tampa Bay loss on being injured, saying, "No matter that physical condition I am in, no matter what foot, shoulder ... I didn't get the job done tonight.''

Newton was not listed on the injury report prior to the game, but it was clear early something wasn't right.

The 2015 NFL MVP had 15 off-target throws (10 over, five under), the most since Chicago's Mitch Trubisky in Week 7 last season and the second-highest number in a game for Newton, according to ESPN Stats and Information.

In two games, Newton has completed only 61 percent of his passes to receivers with three-plus yards of separation, the second-worst percentage in the NFL and down from his 86 percent last season.

Newton was bad under pressure against the Bucs. He was 0-for-10 when under duress -- with three sacks. That was the most such passes he's had in his career without a completion.

Newton completed 25 of 51 pass attempts for 333 yards and no touchdowns against the Bucs. In two games, he has completed 56.2 percent of his passes for 572 yards and no touchdowns with one interception.

His completion percentage comes after a 2018 season in which he completed a career-best 67.9 percent of his attempts in his first year under offensive coordinator Norv Turner.

Newton, whose 4,806 career rushing yards are the most by any quarterback since 2011, also has been a non-factor in the running game. He had two carries for no yards against Tampa Bay after having three carries for career-worst minus-2 yards in the opener.

Should Allen start, it would be the second of his career. He started last year's finale after Newton was shut down the final two games to deal with a sore shoulder that ultimately needed arthroscopic surgery.

Undrafted out of Houston in 2018, he completed 20 of 31 pass attempts for 266 yards and two touchdowns and no interceptions in a win at New Orleans.