"The inside of my ankle has collapsed," Johnson said, according to Les Bowen of The Philadelphia Inquirer.
Johnson has dealt with multiple injuries this season, including ankle, knee, and shoulder ailments. The 30-year-old was sidelined for three of the Eagles' first 10 games.
The three-time Pro Bowler, who's considered one of the NFL's most reliable offensive tackles, last played a full regular season in 2015.
He became the highest-paid right tackle in football after signing a four-year, $72-million extension in November 2019, per Spotrac.
The Eagles have shuffled their offensive line ahead of Monday's game against the Seattle Seahawks, moving veteran left tackle Jason Peters to right guard, sources told John Clark of NBC Sports Philadelphia. Jordan Mailata will reportedly replace Peters on the left side.