Apple previously reached a one-year deal with the Las Vegas Raiders earlier this off-season, but the two sides couldn't finalize the agreement and he became a free agent again.
The New York Giants selected Apple in the first round of the 2016 NFL Draft out of Ohio State. The 24-year-old cornerback has displayed both great potential and inconsistency since entering the league.
Over his four-year career with the Giants and Saints, Apple has recorded three interceptions and 33 passes defensed in 55 games (48 starts). His best season came in 2018, when he notched career highs in total tackles (75), interceptions (two) and passes defensed (14) in 15 regular-season games between the Saints and Giants.
Apple could fill a significant need for the Panthers, who are searching for a starting cornerback opposite Donte Jackson after allowing starter James Bradberry to leave in free agency this off-season.
Carolina added two cornerbacks in last month's NFL Draft -- fourth-rounder Troy Pride Jr. and seventh-rounder Stantley Thomas-Oliver III --- but wanted more experience in its secondary.
Under the new collective bargaining agreement, signing Apple now won't factor into the compensatory draft pick formula for next year.