On July 17, 2014, Johnsen signed with Portuguese club Atlético CP on a two-year deal. In August, he won the award for Player of the Month in the Segunda Liga, after scoring nine goals in five games. His strong performances saw him being scouted by such teams as Benfica, Sporting CP and Belenenses, but the transfer never arrived. According to the Portuguese press Benfica offered €300,000 plus two of their players, but Atletico wanted €500,000 and thus rejected the offer.