Victor Palovaara returned it for this season to Rospiggarna.
The 28-year-old previously represented the Hallstavik club, when they were in the Allsvenskan.
In the quarter-finals at home, he took three victories in the six heats he drove, and also three second places and contributed strongly to the victory against Västervik.
Ahead of Monday evening's first semi-final against Smederna away from home, however, Rospiggarna will have to do without Palovaara.
The ankle joint is broken
He hurt his foot badly during the GP competition in Målilla over the weekend where he was eleventh in the qualifier, but in the last round he flipped around and landed with the bike on his foot.
"Once at home, we have now checked the foot and found that the ankle joint is broken and I will need an operation," he writes on social media.
Palovaara will miss the rest of the playoffs for Rospiggarna.