On 2 September 2019, Frimpong signed a four-year deal with
Celtic.[7] Later that month, he made his professional debut against
Partick Thistle in the
Scottish League Cup quarter-finals.[8] He made an immediate impact, winning the man of the match award on his debut, and going to become a regular in the first team.[9] His speed and skill was highlighted by the media, and made him popular with Celtic fans.[10][11] Frimpong quickly became a fan favorite with his electrifying pace, tenacity, and attacking prowess from the right-back position.[12] On 27 October, Frimpong scored in a 4–0 win against
Aberdeen,[13] his first professional goal.[14] He won his first career honour on 8 December 2019, when Celtic defeated Rangers 1–0 in the
Scottish League Cup Final.[15][16] He was described by Celtic manager
Neil Lennon as "outstanding" and "arguably our best [outfield] player in the first half", although he was sent off early in the second half for a foul on
Alfredo Morelos in the penalty box.[17] In June 2020, Frimpong was voted Celtic's Young Player of the Year for season 2019–20 by the club's supporters.[18]
Bayer Leverkusen
On 27 January 2021, Frimpong signed for German side
Bayer Leverkusen for an undisclosed fee, on a four and a half year deal.[19] On 3 October 2023, he extended his contract until 2028.[20] Frimpong was a key figure in helping Leverkusen win their first Bundesliga title, blitzing past
Werder Bremen 5–0 on 14 April 2024 to end the title race as champions and breaking an eleven-year stranglehold on the league by
Bayern Munich.[21]
International career
Born in the Netherlands, Frimpong is of Ghanaian descent.[22][23] His family moved to England when he was seven years old. As such, he is eligible to play for the
Netherlands,
Ghana, and
England.[23]
In November 2022, Frimpong was included in the final selection of the
Netherlands senior national team for the
2022 FIFA World Cup.[26] Even though, according to an article on the
NOS website, he does not speak a lot of Dutch, he understands match talks and football language.[27] He did not appear in the tournament,[28] as the Netherlands were knocked out by
Argentina in the quarter-finals.[29] He made his first appearance for the Netherlands on 13 October 2023, making a substitute appearance in the
UEFA Euro 2024 qualifying match against
France.