The 6'2" defender was drafted 24th overall by the LA Galaxy in the 2013 MLS SuperDraft. During his rookie season, Opare made six appearances and scored one goal. He made his professional debut for LA in a 2–0 victory over Cartaginés in the 2012–13 CONCACAF Champions League. Overall, he spent two season with the Galaxy (2013-14) and played a total of 1,224 minutes in all competitions before getting traded to D.C. United in July 2014.
Opare had a breakthrough year in 2017 as he played 26 games, 25 from the start, and was named D.