Nolasco saw three different doctors, including foot and ankle specialist Dr. Robert Anderson in Charlotte, N.C., last week. The decision was made to remove the bone fragment in his ankle after conferring with Twins team physician Dr. John Steubs.
Nolasco, signed to a four-year deal worth $49 million before the 2014 season, was 5-1 with a 5.51 ERA in seven starts this year. He also missed nearly a month with right elbow inflammation in early April.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, follow him on Twitter @RhettBollinger and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.