The Twins have agreed to a 1-year contract with middle infielder Alexi Casilla worth $865,000 contract avoiding salary arbitration.  The agreement was announced Sunday.  Casilla had a role as a bench player last season with Minnesota and hit .276 with 1 homerun and 20 RBIs.  He is expected to be the starting shortstop for the Twins in 2011.  Newly signed Japanese import Tsuyoshi Nishioka to be the regular second baseman for the Twins in 2011.