He was signed as a rookie free agent out of Missouri Southern State University by the Philadelphia Eagles in 1997, but quickly released and signed by the Redskins during training camp. He played four seasons with the Redskins and won the team's "Unsung Hero" award in 2000 before signing with the Eagles. While in Philadelphia, Thrash's performance may not have been up to fans expectations, but he accepted multiple roles and was a team player. The team lost the conference championship game each year during his play there. After three seasons with the Eagles, including two as their leading wide receiver, the Redskins eagerly traded a draft pick to the Eagles for the chance to bring him back to Washington. He has been a valued contributor on special teams since his return, and in the later parts of the 2006 season, has made some clutch catches in the end zone and on third downs. According to the team website, Thrash is beginning to earn the moniker "Mr. Clutch."