On October 19, 2022, Agnarsson made his debut for Viborg in a Danish Cup game against Ishøj IF.ISHØJ VS. VIBORG 2 - 3, soccerway.com, 19 October 2022 A few days later, on October 24, 2022, he also made his debut in the Danish Superliga, coming on in the final minutes against AaB to replace an injured Oliver Bundgaard.Ung venstreback kunne ikke få luft og udgik – men weekendens kamp er ikke i fare, viborg-folkeblad.dk, 25 October 2022AAB VS. VIBORG 1 - 3, soccerway.com, 24 October 2022 But after an unfortunate collision with a teammate, Agnarsson had to sit out for a long time with a broken collarbone and was not cleared to play until the end of May 2023.Det forsømte forår: Et uheldigt sammenstød med holdkammerat sendte færing på tribunen, viborg-folkeblad.dk, 23 May 2023
