Brooks signed a four-year professional contract with Hertha after the season, turning down interest from Bayern Munich.

[7][8] His appearances over the season were limited by injury and poor form, and he also missed time in April 2014 while recovering from the application of a large back tattoo, a decision that did not please manager Jos Luhukay.

[9] On December 17, 2014, Brooks opened the scoring for Hertha in a 4–4 draw with Eintracht Frankfurt that saw Berlin throw away a two-goal lead in the final minute.

[15][16] He made his debut on August 13 in the first round of the DFB-Pokal away to fourth-tier Eintracht Norderstedt, but suffered a torn thigh tendon and was substituted in the first half of the 1–0 win, being ruled out for the next three months.

[21] He made his Primeira Liga debut on September 18, replacing António Silva in the 89th minute in the 5–0 home win over Marítimo.

[22] On January 26, 2023, Brooks returned to the Bundesliga, signing a two-year contract with TSG Hoffenheim, for a reported fee of €500,000.

[27] In July 2013, German magazine kicker indicated that Brooks had received a call-up from the U.S. senior national team to feature in a friendly against Bosnia and Herzegovina.

[29] In the opening group match against Ghana, he came on as a halftime injury substitute for Matt Besler and scored the winning goal in the 2–1 victory, a header off Graham Zusi's corner kick.

[31] On June 5, 2015, Brooks scored in a friendly against the Netherlands in Amsterdam as the United States fought back from a 1–3 deficit to win 4–3, their first victory against the Dutch.

[32] Later that month, he was named in coach Jürgen Klinsmann's squad for the 2015 CONCACAF Gold Cup,[33] playing four matches as the team finished fourth.