The Twins played Joe Mauer at first base in their exhibition win over the Red Sox on Friday. Mauer, primarily a catcher, played 18 games at first base last season while Justin Morneau dealt with post-concussion problems. He said working with guest instructors Tom Kelly and Paul Molitor among others has helped him understand the nuances of playing the corner position. "To be able to get some work has helped a lot," said Mauer, who was unsure how much he would have to leave his preferred position of catcher. "I don't know. I just want to be more prepared for whatever they need me to do. If they need me over there a lot, I'll do it. Last year, the more I played over there, the more comfortable I felt."