Wed, 07 Nov 2007 18:09:14 GMT Q&A: Fullback's return has Zephyrs running at full speed in playoffs Bross Sivertson’s senior season is a microcosm of Mahtomedi’s 2007 campaign. The Zephyrs’ 4-0 start ended with a loss at Richfield the game in which Sivertson suffered a concussion.