Simmons is listed as the No. 2 nickel corner on the Giants' first unofficial depth chart, Dan Salomone of the team's official site reports.
Simmons was spotted working with the cornerbacks during Wednesday's practice, Jordan Raanan of ESPN.com reports.
The Giants re-signed Simmons on Friday, Dan Salomone of the team's official site reports.
Simmons tallied 50 tackles (33 solo), including a sack, and added an interception that he returned for a touchdown over 17 games during the regular season.
The Giants plan on using Simmons at linebacker, Jordan Raanan of ESPN.com reports.
Simmons is expected to operate solely as a defensive back next season, Josh Weinfuss of ESPN.com reports.
Thompson totaled 11 tackles against the Buccaneers in the Cardinals' Christmas Day loss.
Simmons recorded eight stops (five solo) Sunday in a loss to the Broncos.
Simmons recorded seven solo tackles during Sunday's 27-17 win over the Rams.
Simmons totaled eight tackles, including one sack, during Sunday's 31-21 loss to the Seahawks.