Coach Ben McAdoo announced the indefinite suspension after practice.
The second-year coach had met with Rodgers-Cromartie on Tuesday and told him that he would not be active for this Sunday's game in Denver because of something the 31-year-old either said or did during Sunday's loss to the Chargers.
Rodgers-Cromartie had left the bench and gone to the locker room during the second half, but he returned. It is not known if the two exchanged words during the game. There was no apparent physical altercation.
McAdoo told the 10-year veteran who joined the Giants in 2014 that he still expected him to practice this week and prepare for the game even though he was not going to play.
Rodgers-Cromartie, who had started three games, reported to the Giants headquarters Wednesday morning and then left. He was not available for comment.
The timing could not be worse for the Giants. They are 0-5 after making the playoffs a year ago, and the suspension gives the impression that McAdoo is losing his team.
The Oakland Raiders adjusted their practice schedule Wednesday because of poor air quality resulting from the wildfires in nearby wine country.
The Raiders took the practice field in smoky conditions with even some ash falling from the sky. The Environmental Protection Agency said the air was "unhealthy" in Alameda, about 40 miles from the fires. The Raiders shortened their practice by eliminating individual drills in an effort to limit the amount of time players spent outside.