On 12 August 2010, Liverpool announced the signing of Poulsen on a three-year contract, for a fee of £4.5m. He was handed the number 28 shirt, previously worn by Damien Plessis. On 19 August 2010, Poulsen made his debut against Turkish team Trabzonspor in the Europa League, in a match won by Liverpool 1–0, in which he had a goal disallowed. Poulsen made his league debut for Liverpool in a 1–0 win against West Bromwich Albion on 29 August 2010. He did not, however, endear himself to the Liverpool fans who often found his performances on the pitch lacking in skill. On 20 November, he produced probably his best display in the centre of Liverpool's midfield against West Ham at Anfield, a game which the home side won 3–0.