Twins icon Joe Mauer will announce his retirement from baseball in a full-page ad in Sunday’s Star Tribune, a source told MLB.com’s Rhett Bollinger on Friday night. The Star Tribune was first to report the news. Mauer, the first overall pick in the 2001 Draft, spent all 15 years of his big league career with the Twins. The six-time All-Star and 2009 American League MVP finishes his career with a .306/.388/.439 batting line.