Per Ben Volin of the Boston Globe, Biggers received a one-year veteran minimum deal from the Patriots, and he's going to be competing with Justin Coleman, Darryl Roberts, Rashaan Melvin, Brock Vereen and any rookies drafted and/or signed in April.
The 28-year-old Biggers is a six-year veteran who was a seventh-round pick of the Tampa Bay Buccaneers in 2010. He spent three years with the Buccaneers, two years in Washington and last year with the Philadelphia Eagles.
Biggers has been used as a slot corner in his career as well as a part-time starter, but he's only had one above-average season by Pro Football Focus grades (via Matt Wincherauk of the Carillon):
MattyWin - SB 51 @MattyWinPats
Biggers had a +7.2 season in 12 according to PFF... His other seasons have been -3.2 ('10), -10.2 ('11), -9.8 ('13), -10.9 ('14), -8.4 ('15)3/29/2016, 7:12:10 PM
The Patriots have a knack for taking unheralded defensive backs and getting the most out of them. Malcolm Butler went from an undrafted free agent to making one of the biggest plays in Super Bowl history to being PFF's 24th-ranked cornerback in 2015.
While Biggers' track record is longer than Butler's, making it unlikely he will make that kind of leap, the Patriots are not afraid to take a chance on someone who has shown some skill in the past. His ability to play cornerback and safety also makes him a valuable asset.
There's nothing for the Patriots to lose in this scenario, as they can cut ties with Biggers without losing much of anything. He gets a chance to resurrect his career with one of the best teams in the NFL.