Guice missed the entire season due to a torn ACL after being picked in the second round of the 2018 NFL Draft. He picked up the knee injury during a 2018 preseason appearance against the New England Patriots.
The second-year running back had 44 yards on 11 carries Thursday at Mercedes-Benz Stadium in Atlanta.
Matt Ryan led the Falcons on an 11-play, 64-yard drive to open the game, but Atlanta missed a field goal to end the possession. Guice ran the ball for seven yards around the left tackle on the Redskins' first offensive play of the game. Guice had a six-yard run on his next carry.
The short run was one of Guice's best highlights from the game. The LSU product took a handoff and ran to his left. He allowed blockers to align in front of him before delivering a vicious stiff-arm, forcing Falcons cornerback Isaiah Oliver to fall to the ground. Guice remained inbounds and ran up the sideline before delivering a punishing shoulder blow to Falcons safety Keanu Neal. The Redskins finished that drive with a 48-yard field goal from Dustin Hopkins to take a 3-0 lead.
"It has been a long time," Guice told reporters. "I knew it was something I needed, to get out there and get my feet under me to get some contact to really see where I'm at."
The Falcons and Redskins exchanged punts at the start of the second quarter. Ito Smith gave the Falcons a 7-3 lead with a 5-yard touchdown run. Hopkins made a 29-yard field goal on the Redskins' next drive, making the score 7-6 at halftime.
Redskins running back Samaje Perine scored a 3-yard rushing touchdowns in the third quarter before the Redskins got another Hopkins field goal from 23 yards out. Hopkins made a 40-yard attempt at the start of the fourth quarter for the final points of the game.
Case Keenum completed 9-of-14 passes for 101 yards for the Redskins. First round 2019 NFL Draft pick Dwayne Haskins completed 7-of-13 passes for 74 yards in relief of Keenum. Ryan completed 9-of-14 passes for 74 yards for the Falcons, before being replaced by backup Danny Etling.
"I think it was a productive night for [Guice]," Gruden said. "It looked like he was decisive in those cuts for the most part. He ran with some power at times and moved the pile when it wasn't there. I was impressed."
The Falcons battle the Jacksonville Jaguars in their final preseason game at 7 p.m. EDT Thursday at TIAA Bank Field in Jacksonville. The Redskins host the Baltimore Ravens at 7:30 p.m. EDT Thursday at FedEx Field in Landover, Md.