"He gotta do what he gotta do, man," Green told TMZ Sports.
"The NFL stands for 'Not For Long,' so you gotta get it while it lasts."
Green signed a four-year, $60-million extension with the Bengals in 2015, and ranks as the league's sixth highest-paid receiver with an average annual value of $15 million. Jones ranks eighth at $14.25 million and was surpassed this offseason by Sammy Watkins and Jarvis Landry.
Jones has been training with soon-to-be Hall of Famer Terrell Owens rather than working out with his NFL employer. Team management is reportedly "uneasy" about Jones' decision, but quarterback Matt Ryan expressed a lack of concern.