Ryan, 6-5, 265, is in his third year in the NFL after being drafted by the Cowboys in the fifth round of the 2004 Draft, 144th overall. Ryan has played in nine games with two starts.
The Boston College product started his career as a defensive end, but moved to tight end with 75 catches for 950 yards and 12 touchdowns. His 12 scores rank second for tight ends in the school's history.
Ryan is the second player to be traded by the Cowboys this preseason.
Dallas also sent linebacker Scott Shanle to the New Orleans Saints for a seventh round draft pick earlier this month.
The Steelers brought Brian St. Pierre in for a look, but only as a member of the practice squad. The…