As a true freshman in 2012, Davis rushed for 275 yards on 52 carries and two touchdowns.[8] Davis took over as the starting running back in 2013, following Marcus Lattimore's departure.[9][10] He rushed for 1,183 yards with 11 touchdowns and was a second-team All-Southeastern Conference (SEC) selection.[11][12][13] As a junior in 2014, he rushed for 982 yards and nine touchdowns.[14]
On December 25, 2014, Davis announced that he would forgo his senior season and enter the 2015 NFL draft.[15]
On May 2, 2015, Davis was drafted by the San Francisco 49ers in the fourth round of the 2015 NFL draft with the 126th overall pick.[19] On September 20, 2015, Davis made his NFL debut against the Pittsburgh Steelers, backing up Carlos Hyde who had to leave the field injured.[20] He finished his rookie season with 58 rushing yards and 38 receiving yards.[21]
On October 23, 2016, Davis had his first-career touchdown against the Tampa Bay Buccaneers.[22] Overall, he finished the 2016 season with 50 rushing yards and a rushing touchdown to go along with 25 receiving yards.[23] On May 5, 2017, Davis was released by the 49ers after failing to trade him during the 2017 NFL draft.[24]
Seattle Seahawks
On May 8, 2017, Davis was claimed off waivers by the Seattle Seahawks.[25] He was waived on September 2, and was signed to the Seahawks' practice squad the next day.[26][27] He was promoted to the active roster on November 14.[28] He finished the 2017 season with 240 rushing yards to go along with 15 receptions for 131 receiving yards.[29]
On March 22, 2018, Davis re-signed with the Seahawks.[30] In Week 4, against the Arizona Cardinals, Davis recorded 21 carries for 101 rushing yards and two rushing touchdowns in the 20–17 victory.[31] Overall, he finished the 2018 season with 514 rushing yards, four rushing touchdowns, 34 receptions, 214 receiving yards, and one receiving touchdown.[32] The Seahawks earned the #5-seed in the NFC.[33] Against the Dallas Cowboys in the Wild Card Round, he had 32 scrimmage yards and converted a two-point conversion in the 24–22 loss.[34]
Chicago Bears
On March 13, 2019, Davis signed a two-year, $6 million contract with the Chicago Bears.[35]
In Davis' first game as a Bear, he rushed five times for 19 yards and caught six passes for 17 yards as the Bears lost to the Green Bay Packers by a score of 10–3.[36] He was released on November 9.[37] In the 2019 season, he played in 12 games and recorded 13 carries for 27 rushing yards to go along with seven receptions for 22 receiving yards.[38]
Prior to the 2020 season, Davis was listed as one of the backups on the depth chart behind All-Pro Christian McCaffrey.[40] In Week 2, McCaffrey suffered an ankle injury and was place on injured reserve, making Davis the Panthers' starting running back.[41] In Week 4 against the Cardinals, Davis recorded 111 yards from scrimmage and his first rushing touchdown of the season during the 31–21 win.[42] In Week 5 against the Atlanta Falcons, Davis recorded 149 yards from scrimmage and a receiving touchdown during the 23–16 win.[43] In Week 14, against the Denver Broncos, he had 93 scrimmage yards and two rushing touchdowns in the 32–27 loss.[44] In the 2020 season, Davis had 165 carries for 642 rushing yard and six rushing touchdowns to go along with 59 receptions for 373 receiving yards and two receiving touchdowns.[45]
Atlanta Falcons
On March 25, 2021, Davis signed a two-year, $5.5 million deal with his hometown Falcons.[46][47] He entered the season as the Falcons starting running back, but lost playing time as the season went on to Cordarrelle Patterson. He finished the season second on the team in rushing with 503 yards and three touchdowns along with 259 receiving yards and one touchdown.[48][49]
On May 2, 2022, Davis was released by the Falcons.[50]
Baltimore Ravens
On May 10, 2022, Davis signed with the Baltimore Ravens.[51] He was released by the Ravens on December 10, 2022.[52]
Davis announced his retirement on February 19, 2024.[53]