Matthews spent an injury-plagued season with the Buffalo Bills in 2017, appearing in 10 games (seven starts) and recording 25 receptions for 282 yards and two touchdowns -- careers lows in each category.
The 6-foot-3, 212-pound Matthews spent his first three seasons with Philadelphia after the Eagles made him a second-round draft pick out of Vanderbilt in 2014.
Matthews had eight touchdown catches in each of his first two seasons and established career highs with 85 receptions for 997 yards while appearing in all 16 games in 2015.
With the Patriots losing Danny Amendola to free agency, Matthews will help fill the void in the slot. He had 225 catches in his three seasons with Philadelphia.
Acquired by Buffalo in a trade prior to last season, Matthews dealt with myriad injuries, including a fractured thumb and a knee issue.
Matthews announced via social media in December that he underwent surgery on his left knee and right ankle.