League sources told ESPN and NFL Media on Tuesday that Jackson sustained the injury during the Eagles' 24-20 loss to the Atlanta Falcons on Sunday night. One doctor recommended surgery, which would have sidelined the 32-year-old wideout for about six weeks, but Jackson opted against the procedure, according to ESPN.
Jackson exited early in the first half against the Falcons, playing only 11 snaps. He is expected to miss the Eagles' Week 3 matchup against the Detroit Lions and the team's Week 4 contest against the Green Bay Packers on Thursday Night Football.
The Eagles reacquired Jackson in a trade with the Tampa Bay Buccaneers in the off-season. In his return to the franchise, he recorded eight receptions for 154 yards and two touchdowns during Philadelphia's Week 1 victory over the Washington Redskins.
Against the Falcons, he started the game but registered no catches prior to his early departure.
Fellow Eagles wideout Alshon Jeffery could also miss Sunday's matchup against the Lions after he suffered a calf injury versus the Falcons. He saw only six snaps against Atlanta.