Brenden is a homegrown talent starting his career at Philadelphia Union's academy and then moving to amateur side Bethlehem FC and eventually returning to Philadelphia Union, where he would make his MLS debut. His two years in MLS led to Red Bull Salzburg signing him, where he won his first piece of silverware, which was the Austrian Cup. Eventually, he made his first big move, joining Premier League side Leeds United and then playing in the Championship, where he had a key role in helping them get promoted to the Premier League again. His performances in the MLS earned him a call-up in 2019 to the USMNT for CONCACAF Nations League matches against Cuba and Canada, and he eventually earned his first cap against Cuba in 2020.
Philadelphia Union: Brenden is a homegrown talent who worked his way from Philadelphia Union's academy to their first team in the MLS. Brenden's first season in MLS in 2019 was great, in which he finished second in MLS Rookie Of The Year, but it was his second season in 2020 that was phenomenal. He finished the season in 2020, amassing 31 appearances and scoring five goals, winning numerous accolades, namely making it to the list of the 2020 Best MLS XI and the MLS Is Back Tournament. Overall, he amassed 57 appearances for the Philadelphia Union, in which he had seven goals and six assists.
Red Bull Salzburg: Brenden's performances in the MLS led to Red Bull Salzburg signing him for an undisclosed fee in 2020. It was later announced by the Philadelphia Union that it was the highest transfer fee paid for a homegrown player from the MLS. He won his first piece of silverware in his career when RB Salzburg beat LASK 3-0 in the finals of the Austrian Cup. Overall, he amassed 66 appearances for Red Bull Salzburg, in which he had 13 goals and 15 assists.
Union Berlin: Brenden Aaronson had joined Premier League side Leeds United in 2022 and had a minor change after Leeds got relegated. Upon getting relegated to the Championship for the 2023-2024 season, Leeds United loaned Brenden Aaronson to Bundesliga side Union Berlin for the remainder of the season. There, he amassed 38 appearances in which he scored two goals and had two assists.
Leeds United: Leeds announced the signing of Brenden Aaronson in 2022 on a five-year contract, and he made his senior debut for them in the season opener in a 2-1 win against Wolves. He also scored his first goal for Leeds in a memorable 3-0 win against rivals Chelsea. Brenden's first season at Leeds was great up until they got relegated to the Championship, which led to him playing on a season-long loan for Union Berlin. After returning from Union Berlin, Brenden returned to Leeds United for the 2024-2025 season and played a crucial role in them winning the Championship. This is truly Brenden's best career performance since he scored an all-time career high of 11 goals in a season and had three assists as well. Overall, Brenden has amassed 87 appearances for Leeds in which he has scored 11 goals and has six assists.
Brenden's exploits in domestic football, namely his years in the MLS, led to him earning his call-up to the senior team for the CONCACAF Nations League matches against Cuba and Canada in 2019. However, it was up until 2020 when he actually earned his first cap and played the entire 90 minutes in a 1-0 win against Cuba. Brenden scored his first goal for the USMNT in a 6-0 thrashing of El Salvador in December 2020. Brenden Aaronson was also a part of the 2022 FIFA World Cup squad and played in all three of their group games. Overall, he has earned 47 caps for the USMNT, scoring eight goals.