Jackson's 2013 season was the worst of his 10-year NFL career. He played in 12 games but posted just 543 yards with six touchdowns. A member of the 10,000-yard club, it was the only time he didn't top 1,000 since his rookie year.
Here's the other training-camp injuries we're monitoring from around the league:
- Cowboys second-round pick Demarcus Lawrence was carted off the field. He was unable to place much pressure on his right foot, per NFL Media's Desmond Purnell. Jerry Jones said Lawrence will undergo X-rays on his foot and ankle. The Cowboys fear that the No. 34 overall pick broke his foot, per NFL Media Insider Ian Rapoport.