He played college football for the Arizona State Sun Devils and was selected by the Green Bay Packers in the seventh round of the 2011 NFL Draft.

As a child, Guy was placed in special education classes, as he had been diagnosed with attention deficit hyperactivity disorder, dyslexia, and dyscalculia.

[1] Guy attended Western High School in Las Vegas, Nevada, where he recorded 238 tackles (171 solo), 30.5 sacks and three fumble recoveries in his three seasons.

[2] He committed to the Sun Devils on December 19, 2007, choosing ASU over Arizona, Michigan, Nebraska, Oklahoma, Oregon, and Tennessee.

On September 24, 2014, Guy was claimed off waivers by the Baltimore Ravens after spending the first 3 weeks of the regular season with the Chargers.

In the AFC Championship Game against the Jacksonville Jaguars, Guy had 6 tackles and 1 sack to help the Patriots reach the Super Bowl.

[13] Guy helped the Patriots reach Super Bowl LIII where they defeated the Los Angeles Rams 13–3.

[14] During Week 8 of the 2019 season, Guy recorded his first career interception off of a botched shovel pass by Browns quarterback Baker Mayfield in the 27–13 win.

[15] In week 9 against the Ravens, Guy recovered a fumble forced by teammate Kyle Van Noy on running back Mark Ingram II in the 37–20 loss.

[16] In week 11 against the Eagles, Guy recovered a fumble forced by teammate Danny Shelton on Carson Wentz in the 17–10 win.