Henrik Larsson has left Helsingborg following their relegation from the Swedish top flight on Sunday.
Lionel Messi, Neymar and Saul Niguez are among the 10 nominees for the FIFA Puskas Award 2016 for the best goal of the year.
Helsingborg are investigating crowd trouble that saw manager Henrik Larsson's son attacked on the pitch after the club's relegation was confirmed.
Karlsson, 18, has scored four goals and registered two assist so far this season for Falkenberg.
A match between two Swedish sides was abandoned after a pitch invader assaulted Ostersunds goalkeeper Aly Keita on Monday.
Jordan Larsson has been held back from participating in Sweden's Olympics campaign by his father Henrik.