Wide receiver Devin Thomas, who had an NFL career of unmet expectations, left Chicago Bears camp Sunday and retired from football.

Shortly after the Bears announced he had left the team, Thomas announced his retirement via Twitter, saying only, "I have decided to retire from the NFL."

Thomas had signed for $1 million and one year with the Bears in late March. They were hoping he would fill in the reserve wide receiver/special teams ace position that Sam Hurd had been signed to perform last year. Hurd was arrested in December on federal drug charges.

The Bears were using Thomas in all special teams, and he had been one of the most targeted wide receivers in scrimmages. His departure leaves wide open a spot in the receiver corps for second-year player Dane Sanzenbacher, rookie West Texas A&M wide receiver Brittan Golden, or several others. Golden has been impressive in the passing game throughout camp.

Brandon Marshall, Devin Hester, Earl Bennett, rookie Alshon Jeffery, and injured veteran Eric Weems would appear to be the first five on the Bears receiver list, although the depth chart for the first preseason game has not yet officially been released.

Thomas had been cut by the Washington Redskins in 2010 after it was reported he had been sleeping in a team meeting. He had been drafted originally by the Redskins in the second round in 2008. He played for the Giants during their Super Bowl run last season and had three catches on the year. Thomas had 43 career catches for 482 yards and three touchdowns, all of them in 2009. He also made 60 kick returns for a 24.1-yard average.

Follow Bears reporter Gene Chamberlain on Twitter @CBSSportsNFLCHI.