He started his professional career in Helsingborgs IF, where his father Sven Åke played almost 350 matches. In 2010, Landgren transferred to Italian side Udinese. He did not play any first-team matches for the club, and was loaned out to Willem II during the 2010–11 Eredivisie season. He joined Norwegian side Fredrikstad on loan in mid-2011, and joined the club permanently ahead of the 2012 season. After Fredrikstad was relegated from Tippeligaen, Landgren moved back to Sweden where he joined Halmstads BK on loan in April 2013. A year later, he transferred back to his home town club Helsingborgs IF. However, an injury kept him out of play for the whole 2014 season.