Financial terms were not disclosed in the report.
Davis was reinstated by the NFL last week after a year-long suspension for violating the league’s substance abuse policy for a second time after he was arrested and charged with driving under the influence in February 2014.
Davis, 29, spent his first six NFL seasons with the Washington Redskins, tallying 162 catches for 2,043 yards and 13 touchdowns in 72 games.
In 2013, he only caught seven passes for 70 yards in 10 games.
The Patriots' depth chart is crowded at the tight end position with All-Pro Rob Gronkowski, Tim Wright, Michael Hoomanawanui, Scott Chandler and A.J. Derby, who the team selected in the sixth round of last month’s NFL draft.
- Scooby Axson