The Twins designated Rucinski for assignment Sunday, Brandon Warne of ZoneCoverage.com reports.
With the Twins needing to clear a 40-man roster spot for new fifth starter Nik Turley, Rucinski, a 28-year-old who had given up five runs over 4.1 innings in his previous two appearances with the big club this season, was the casualty. Unless another team elects to bring Rucinski aboard its 40-man roster via waivers or trade, the right-hander probably will remain in the Twins organization and work as a swingman for Triple-A Rochester.