Barber has apparently already filed the appropriate paperwork and will reportedly explore his free agency opportunities.
Barber, who turns 36 in April, retired in 2007 after playing 10 seasons for the Giants.
After retiring from the NFL, Barber took a job at NBC that paid him $300,000 per year. His contract was terminated by the network after it was revealed that Barber was dating a former NBC intern.
Barber is also going through a divorce and his ex-wife claims he can't pay his divorce settlement.