[1] Prior to joining Wesleyan Christian Academy in the United States in 2004, Finnur played for KR-b in the 2. deild karla and the Icelandic Basketball Cup from 2002 to 2004.

[4] He helped the club to the 2011 Icelandic championship, scoring 20 points in the fourth and deciding game of the finals series against Stjarnan.

[19] Finnur left Haukar after the season and signed as a strength coach with Hungarian club Ceglédi EKK.

[22] After playing one game for KR-b in the 2. deild karla on 11 November, he was called up to the main KR squad.

[25] In February 2020, Finnur Atli left KR and joined rival Reykjavík club Valur.

Finnur Atli is the younger brother of former Icelandic national team member Helgi Már Magnússon.