Whakaoti i te rerenga e whai ake nei: I te tau e whai ake nei i takaro a Karlsson i te kapa motu o Sweden i raro i te 18 tau i te 1982 IIHF European U18 Championship, e rua nga tohu i roto i nga keemu e rima ka wikitoria i te mētara koura. I tākaro hoki a Karlsson i te kapa ā-iwi o Sweden i raro i te 20 tau i te 1983
Ko te 1984 World Junior Ice Hockey Championships. I te wa 1982/83, i whakawhiwhia a Karlsson ki te purei i te Modo Hockey o te Elitserien, te riiki hockey hukapapa o Sweden. I roto i ona tau tuatahi e rua ki te kapa kaore ia i kaha ki te whaainga i tetahi whaainga, a i te waa 1983/84 i heke te kapa ki te wehenga 1. Heoi, i tere te whakatairanga a Karlsson raua ko Modo ki Elitserien i te waa e whai ake nei.