Washington, 30, posted what seemed to be a farewell message to Seahawks fans on his Twitter account Tuesday afternoon.
"Seattle It's Been Awesome A Ride, Got Nothing Bad 2 Say About The Gr8 NW #12thMan StandUp!!! Like always... #LetsGetIt," he wrote.
Schneider complimented the way Washington handled the news that the Seahawks were letting him go.
"He did a phenomenal job here. The fans love him. He's such a pro. He really handled himself with extreme class with Pete (Carroll) and I when we talked with him and understood what we were doing," Schneider said.
Washington had 1,140 combined yards on kickoff and punt returns last season, with one touchdown. He has eight career kickoff return touchdowns.
Harvin had 574 yards and a touchdown on kickoff returns for the Vikings last season. He has five career return touchdowns.
Washington revitalized his career in Seattle after a devastating knee injury suffered with the New York Jets.
He set a career high by averaging 29.0 yards per kickoff return last season. He also has four kickoff returns for touchdowns since joining the Seahawks in 2010, tied for the NFL lead during that span.
Releasing Washington would reduce his contract's salary-cap footprint from $2.875 million to $750,000 for the coming season.
Information from ESPN NFL Insider Adam Schefter, ESPN.com NFC West blogger Mike Sando contributed to this report and The Associated Press was used in this report.