On May 12th, the Washington Nationals placed Ryan Zimmerman on the 10-day DL and selected the contract of Mark Reynolds from the Syracuse Chiefs. In doing so, they were able to purchase the contract of an All-Star first baseman from Triple-A to replace their currently injured All-Star first baseman.
Last season both players represented the National League in the 2017 All-Star Game. Zimmerman from the Nationals and Reynolds from the Colorado Rockies. So how is it possible that the Nationals were able to sign a reigning All-Star to a minor league contract in mid-April?