[3][4] As a sophomore in 2016, Walls slashed .355/.479/.516 with six home runs, 46 RBIs, and 14 stolen bases over 63 starts, earning All-ACC Second Team honors.

[8][9] Walls signed with the Rays and made his professional debut with the Hudson Valley Renegades of the Low–A New York–Penn League, batting .213 with one home run over 46 games.

[10] In 2018, Walls played with the Bowling Green Hot Rods of the Single–A Midwest League (with whom he earned All-Star honors), slashing .304/.393/.428 with six home runs, 57 RBI, and 31 stolen bases over 120 games.

[18][19] He made his debut that day and recorded his first MLB hit, a double off of Toronto Blue Jays starter Robbie Ray, during the game.

[20] Walls ended the 2021 season with Tampa Bay slashing .211/.314/.296 with one home run, 15 RBI, and ten doubles over 152 at-bats.

[27] In March 2022, Walls retweeted a statement from Ron DeSantis criticizing the NCAA's decision to allow Lia Thomas to compete in women's swimming competitions.