Born in San-Pédro, Kouassi began his career at local side Séwé Sports before moving to Servette FC in the Swiss Super League in 2009. He made his professional debut on 1 November that year, playing the full 90 minutes of a goalless away draw with FC Winterthur.
On 16 July 2013, Kouassi transferred to FC Sion of the same league, on a three-year deal.[2] He played five of six matches as they won the Swiss Cup in 2014–15, including the 3–0 final win over FC Basel on 7 June.[3]
New England Revolution
Kouassi joined the New England Revolution of Major League Soccer on 1 February 2016, joining as a designated player effective from July.[4] However, a major injury to his right knee ruled him out for over a year, and he did not debut for his new team until 19 March 2017 in a 2–1 loss to FC Dallas; though used for only 45 minutes per game in pre-season due to this injury, he made it to 79. He was praised for his performance by head coach Jay Heaps and teammate Scott Caldwell.[5]
On 1 June 2017, Kouassi scored his only goal for the Revs in a 2–2 draw with New York City FC.[6] In September, he received straight red cards in heavy away losses to Atlanta United FC (7–0) and Orlando City SC (6–1), in the 16th and 11th minutes of the respective games.[7][8]
Return to Sion
Kouassi returned to Sion on 15 February 2018, the last day of Switzerland's transfer window.[9] In February 2020, before the Super League was postponed due to the COVID-19 pandemic, he was sent off in consecutive matches against FC Zürich and Neuchâtel Xamax FCS. The latter dismissal earned him a public criticism by club owner Christian Constantin, who considered it to have "murdered" the entire team's efforts.[10]
Club captain Kouassi and eight other players were sacked by Sion on 20 March 2020, having refused a pay-cut amidst the pandemic.[11]
On 13 September 2020, Kouassi signed for Pau FC.[13]
International career
Kouassi earned one cap for the Ivory Coast on 10 August 2011. He replaced Gervinho in the last minute of a 4–3 friendly win over Israel at the Stade de Genève, the home of his then-club Servette.[14]