Granqvist was born at Karolinska Hospital in Solna on 25 October 1967 and grew up on Backvägen in Solna. His father, Karl-Ivar, co-created "The Bench" – a place at Solna Centrum shopping mall where men gathered to hang out while their wives were shopping. Since it was forbidden to talk about politics and religion, much talk on "The Bench" came to be about sports. As young, Granqvist was bad at sports and not much of an athlete. When he was six to seven years old, his father sent him to a football practice at Råstasjön's sports ground. It rained and they lined up in a row and the coach threw balls so they could practise headers. Granqvist struck the ball once and it hurt badly. Then he went home. And in ice hockey he could only stop on ice skate in one direction and as a result he always ended up in the snow bank. Instead, he acted as a referee and was commenting the games at the same time. He did though make 38 points in 50 games whilst playing floorball in Division 1 for IBK Solna. As a child in Solna, Granqvist used to sit with big headphones and listen to Sportextra sports show in Sveriges Radio P4. At the same time he made own notes. With different color pencils he recorded goals, penalties and other important events in the ice hockey matches. When there were no matches, he and a friend made up own onces. There was no doubt that Granqvist would become a sports commentator in radio. Ten years old, in the car on the way to and from the summer house, the Granqvist family passed Uppsala's then ten traffic lights while Lasse referred a race against the traffic signals. When the kids in the yard had a cycling competition, Granqvist used to jump on a table in the sandbox and comment on the race even though he did not see the cyclists. As they approached, he got put together a summary. When Granqvist went out with a car with his mom and dad, he commented on the competition between red and blue cars.
