Sundgren wuxuu waxbarashadiisa jaamacadeed ka bilaabay Karlstad guga 2009 wuxuuna u ciyaaray kooxo kala duwan inta lagu guda jiray muddadan. Xilli ciyaareedkii 2010-2011, wuxuu la ciyaaray saddex kooxood oo kala duwan. Taxanaha Elite, wuxuu ka booday kooxda Karlstad oo uu ka tagay Oskar Eriksson sanadkii 2008, isagoo ku biiray Oskar walaalkiis Markus Eriksson, iyo sidoo kale Marcus Franzén iyo Henric Jonsson oo sameeyay Kooxda Sundgren. Waxa kale oo uu ka haray kooxda Sweden ee Universiade 2011
, oo hogaaminaya kooxda Alexander Nordgren, Axel Rosander iyo Johan Spiik, in kasta oo kooxdu ku dhammaysay tartanka kaalinta 8aad. Sundgren wuxuu iska dhaafiyay kooxdiisa, Lag Sundgren, oo loogu talagalay Karlstad ee Horyaalka Curling-ka ee ragga ee Sweden, isagoo ku guuldareystay final aad u dhow oo ay la yeesheen asxaabtiisii hore ee Oskar Eriksson, Kristian Lindström, Alexander Lindström, iyo Henrik Leek. Wuxuu dib ugu soo biiray iyaga 2011 Horyaalka Curling Junior ee Adduunka, isagoo ku guuleystay billad dahab ah. In kasta oo Sundgren uu si rasmi ah u ahaa beddelka oo uusan ciyaarin wax ciyaaro ah wareega wareega, wuxuu ciyaaray ciyaarihii guusha ee muhiimka ahaa ee semi-finalka iyo finalka markii Henrik Leek uu ku jiray cimilada oo uu lagama maarmaan u ahaa guusha bilada dahabka.