Grace had eight total tackles Thursday, when the Falcons fell to 0-4 in the preseason with a 13-7 loss to the Jaguars, and he added an interception, a pass breakup and a special-teams tackle.
The 6-foot-1, 223-pound speedster from the University of Miami, whom the Hurricanes dismissed before his senior season in 2016, played inside as if he had a jet pack on his back, covering ground quickly time after time.
"We were excited to see Grace," Quinn said of a player who missed one preseason game because of an injury. "We certainly have some tough decisions at that spot. ... Our linebackers can run; it shows up on tape."
The Falcons are set at two linebacker positions with rising second-year players Deion Jones in the middle and De'Vondre Campbell on the strong side. Rookie Duke Riley from LSU may end up starting on the weakside in part because of a preseason injury to LaRoy Reynolds.
Also, at times pass-rusher Vic Beasley Jr. will line up at outside linebacker when he's not playing defensive end.
Converted safety Kemal Ishmael is a factor at linebacker as well, and he helps on special teams. Grace made his initial mark at Miami as a special-teamer.
"He missed a year, but we were aware of his speed," Quinn said. "He fits into what we do at linebacker."