The team is expected to announced his departure by the end of the week, The Baltimore Sun reported. But Ayanbadejo addressed his fans on Twitter Thursday.
"I would like to thank the city of Baltimore and the Ravens organization for an amazing ride," Ayanbadejo said on Twitter. "We will forever be united as champions!"
The team has been releasing older players like Ayanbadejo, who will soon celebrate his 37th birthday. Cornerback Chris Johnson, 33, and fullback Vonta Leach, 31, will be the oldest players on the roster.
Ayanbadejo joined the Miami Dolphins in 2003 after several years on practice squads and with non-NFL teams. He played in three Pro Bowls, two while with the Chicago Bears and one with the Ravens.
Last year, Ayanbadejo enthusiastically backed a Maryland referendum to legalize same-sex marriage. He and Chris Kluwe of the Minnesota Vikings were to be honored Thursday by Straight for Equality for their stand on the issue.