With starting quarterback Daniel Jones still dealing with a neck injury, the Giants worked out quarterbacks Matt Barkley and Ian Book.
The Giants elevated Tommy DeVito from the practice squad Sunday night to back up Tyrod Taylor.
Barkley makes sense, having spent three years with head coach Brian Daboll when both were in Buffalo.
Barkley became a free agent on Sept. 1 when the Bills released him from injured reserve.
The Eagles made Barkley a fourth-round choice in 2013. After two years in Philadelphia he spent time with the Cardinals, Bears, 49ers, Cardinals again, Bengals, Bills, Titans, Panthers, Falcons and Bills again.
Barkley has started seven games in his NFL career and has thrown 11 touchdowns and 22 interceptions.
Book has spent time with the Saints, Eagles and Patriots since New Orleans made him a fourth-round pick in 2021.
The Bills also worked out receiver Damiere Byrd among others.