The staff changes were finalized on Monday.
Brunansky, the right fielder on Minnesota's 1987 World Series championship team, was the hitting coach for Triple-A Rochester this year, and Cuellar was the pitching coach. Steinbach has been a guest spring training instructor but not a full-time coach until now. The native of New Ulm, Minn., and former University of Minnesota star played three of his 14 major league seasons with the Twins.
Cuellar has been a minor league coach for the Twins organization for nine years. He's credited with helping two-time Cy Young Award winner Johan Santana develop his trademark changeup.