Armstrong, 30, hasn't had the typical NFL story, as he made his professional debut with the Odessa Roughnecks of the Intense Football League in 2006, an indoor football league that eventually merged with United Indoor Football to create the Indoor Football League. In 2007 and 2008, Armstrong played in the Arena Football League with the Dallas Desperados.
It wasn't until 2008 that he earned his way on to the Miami Dolphins practice squad and he has bounced throughout the league since. After stints with the Washington Redskins, Jacksonville Jaguars and a second-stint with the Dolphins, Armstrong was signed by the Cowboys in November 2012 and played in just one game with the team.
He was signed to a reserve/future contract after the season, but the Cowboys released him on March 27. However, he's now back with the Cowboys after a free agent visit to the NFC East-rival Giants may have changed the Cowboys' mind about his release.
In 30 career NFL appearances, Armstrong has 54 receptions for 986 yards and five touchdowns.