Demps plans to report to the Bucs on Monday, Demps' agent Daniel Rose of Gridiron Sports said.
Rose told me: "We visited them during the off season and the Bucs were supportive of his track decision, and now that the track season is over he's ready for football."
Demps, a former track and field athlete, was placed on injured reserve last year after signing a three-year deal with the New England Patriots. He was traded from the Pats to the Bucs, along with a seventh-round pick in the 2013 draft, for running back LeGarrette Blount.
Demps was placed on the Reserve/Did Not Report list before camp and Tampa Bay will have to make room on their 53-man roster once he's activated.
Follow Ian Rapoport on Twitter @RapSheet.