A full international between 1974 and 1981, he won 45 caps for the Sweden national team and represented his country at the 1978 FIFA World Cup.
Already during his first season for Malmö FF, the club, much to his goal scoring capacity won the top Swedish football league, Allsvenskan in 1974, under English manager Bob Houghton.
When he then left for Karlsruher SC in the Bundesliga during the 1976–77 season, his former Swedish club only came second in Allsvenskan, behind Halmstad BK, which were led by another Englishman, Roy Hodgson.
After scoring a goal for Sweden in the 1978 World Cup in Argentina against Brazil, the well bearded Sjöberg become interesting for an Arabian Sheik, who bought him for a club in Saudi Arabia.
Sjöberg was capped 45 times for the Sweden national team and scored a goal against Brazil in the 1978 FIFA World Cup.