[2] He played for the New York Rens at the Nike Elite Youth Basketball League, helping the team reach the Peach Jam semifinals.

[7][8] Barlow made his proper NBA debut with the Spurs on November 2, 2022, by getting two points and three assists in a 143–100 blowout loss against the Toronto Raptors.

[9] On January 28, 2023, in 126–110 loss to the Rio Grande Valley Vipers in the NBA G League, Barlow finished with a double-double career-high game of 32 points, 10 rebounds, and 3 blocks for Austin.

[10][11] On April 2, 2023, Barlow recorded his first double-double in the NBA with 12 points and 10 rebounds alongside a season-high 5 assists in a 142–134 overtime win over the Sacramento Kings.

[12] In the final game of Barlow's rookie season just a week later, he recorded career-highs of 21 points and 19 rebounds in a 138–117 win over the Dallas Mavericks.