Atlanta United announced on March 9, 2023 that Luke Brennan had signed a Homegrown contract, effective Jan. 1, 2024. Brennan was a member of the club's inaugural Academy class and progressed through Atlanta United's Academy and Atlanta United 2 before debuting with the First Team in 2023.
Brennan became a regular in the squad in the 2025 MLS season, starting six games in 14 appearances as well as starting two of his three appearances in Leagues Cup. Toward the end of the regular season, Brennan made the U.S. roster for the 2025 FIFA U-20 World Cup and added an assist in a win against France in the group stage and another assist against Italy in the Round of 16.
The winger had a breakout year in 2022 when he played over 1,000 minutes for ATL UTD 2. in 2023, he played with the club's MLS NEXT Pro affiliate and made 25 starts. He scored four goals and added five assists. Brennan received two Short-Term Agreement call-ups to the First Team in 2023, making his MLS debut as a substitute on June 21 against NYCFC.
2025 (Atlanta United / Atlanta United 2): MLS: Made six starts in 14 appearances. Leagues Cup: Started two of his three games played and tallied one assist. MLS NEXT Pro: Started all six games he appeared in, scoring twice.
2024 (Atlanta United / Atlanta United 2): MLS: Made seven appearances, all coming off the bench. He totaled 147 minutes and two shots. U.S. Open Cup: Brennan played in all three Open Cup matches for ATL UTD in 2024, making two starts. MLS NEXT Pro: Made 12 appearances, including 10 starts with ATL UTD 2. Scored four goals and recorded two assists in 894 total minutes played.
2023 (Atlanta United / Atlanta United 2): MLS: Made his MLS debut on June 21 vs. NYCFC coming on as a substitute. MLS NEXT Pro: Made 25 starts and scored four goals with five assists for ATL UTD 2. Played 2,124 total minutes and had 25 total shots with nine on target.
2022 (Atlanta United 2): USL Championship: Made 27 appearances, 11 starts, for ATL UTD 2 in the USL Championship. Scored two goals and had two assists in his first full season playing with the team. Scored his first professional goal on July 7, 2022 against Birmingham Legion FC.
International: Brennan earned his first call-ups for the U.S. U-20 national team in 2024. He made his debut on Oct. 20 in a friendly against Chile. In 2025, Brennan was named to the U.S. roster for the 2025 FIFA U-20 World Cup, where he made four appearances and tallied two assists, helping the U.S win its group and advance to the quarterfinals. Brennan has made 12 appearances with the U.S. U-20s and recorded one goal and three assists.
