He made his debut in the Premier League in Cardiff's first match of the 2018–19 season, a 2–0 defeat to A.F.C. Bournemouth, before scoring his first goal in the top division in a 4–1 defeat to Chelsea in September 2018. Bamba scored a further 3 goals during the season, including in wins against Brighton & Hove Albion and Southampton. Having missed only one match during the course of the season, he was ruled out for the remainder of the campaign after rupturing his cruciate knee ligaments in a defeat against Wolverhampton Wanderers on 5 March 2019.