May was 10-13 with a 4.87 ERA at Double-A Reading. He was Philadelphia's top prospect before his so-so season.
The Phillies finished 81-81 in 2012, ending their string of postseason appearances at five. They still have to fill several needs, including another starting outfielder and a third baseman.
AP Sports Writer Dave Campbell in Minneapolis contributed to this report.
Follow Rob Maaddi on Twitter: https://twitter.com/RobMaaddi
Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.