Head coach Ben McAdoo made the announcement about the 31-year-old Rodgers-Cromartie, who started four of the winless Giants' five games this season.
"DRC came in yesterday, we had a conversation that was personal upstairs and he came in today and decided to leave," McAdoo told reporters. "We will suspend him."
NFL Network's Ian Rapoport reported the suspension stemmed from a "heated" argument between Rodgers-Cromartie and McAdoo that began when the cornerback was pulled from Sunday's 27-22 loss against the Los Angeles Chargers. Rodgers-Cromartie felt he was being a "good soldier" by taking the slot cornerback role, according to Rapoport, and disagreement apparently dragged into Tuesday's conversation with McAdoo.
Giants safety Landon Collins said he believed the issue occurred from what he called an "altercation" between McAdoo and Rodgers-Cromartie on Sunday, according to ESPN.
McAdoo, when asked about the length and reason for the suspension, said, "That's all I have for you right now."
In a text message, Rodgers-Cromartie told ESPN he will be returning to the team Thursday.
Rodgers-Cromartie has one more season left on the five-year contract he signed before the 2014 season. He has 26 tackles and a half-sack this season.
The 6-foot-2, 203-pound Rodgers-Cromartie is in his 10th NFL season since being drafted No. 16 overall by the Arizona Cardinals in 2008. Before coming to the Giants, he also spent time with the Philadelphia Eagles and Denver Broncos.