New England Patriots Harris was selected by the
New England Patriots in the third round with the 87th overall pick of the
2019 NFL draft. He made his professional debut in the team's Week 7 33–0 victory over the
New York Jets, rushing for 12 yards on four carries. It would be his only carries for the season as he was a healthy scratch for most of his rookie season. On September 7, 2020, Harris was placed on injured reserve with a broken finger. He was activated on October 5, 2020. In Week 4 against the
Kansas City Chiefs, he had 17 carries for 100 rushing yards in the 26–10 loss. In Week 8, against the
Buffalo Bills, he had 16 carries for 102 rushing yards and his first career rushing touchdown in the 24–21 loss. In Week 10, Harris rushed the ball 22 times for 121 yards, both career highs, helping lead the Patriots to a 23–17 upset victory over the
Baltimore Ravens on
Sunday Night Football. He was placed back on injured reserve on January 2, 2021. He finished the season as the Patriot's leading rusher with 691 yards and two touchdowns through 10 games. Harris was the team's primary starter for the 2021 season. He started the first nine games of the season, though a
concussion sustained in Week 9 kept him out of the Week 10 game against the
Cleveland Browns. He returned as the starter for Week 11. He had 100+ yard performances in Week 1 against the
Miami Dolphins, Week 6 against the
Dallas Cowboys, and Week 7 against the New York Jets. He was mostly ineffectual, however, during the Week 3 and 4 losses against the
New Orleans Saints and the
Tampa Bay Buccaneers respectively, being held to only 10 total yards rushing combined between the two games. Starting in Week 8, he began to split carries with backup
Rhamondre Stevenson. He finished the season with a career-high 929 rushing yards and was second in the league with 15 rushing touchdowns. Harris entered the 2022 season as the Patriots starting running back, with Rhamondre Stevenson close behind him. A hamstring injury suffered in Week 5 slowed down his production and allowed Stevenson to overtake him as the lead back, but still split carries with the second-year player. He suffered a thigh injury in Week 12 and missed the next four games. He finished the season with 462 rushing yards and three touchdowns.
Buffalo Bills On March 21, 2023, Harris signed a one-year, $1.7 million contract with the
Buffalo Bills. Harris scored his first touchdown as a Bill during a 38–10 Buffalo win against the
Las Vegas Raiders in week 2. During week 6 against the
New York Giants, Harris was injured after he collided with Giants linebacker
Bobby Okereke on what would be his only carry of the game. He was taken off the field via ambulance and was later diagnosed with a neck sprain. He was placed on injured reserve on October 20. He became a free agent after the 2023 season. Harris announced his retirement from professional football via
Instagram on March 25, 2024. == Career statistics ==