I think this was in a fanshot some time ago. It is a reflection of Heyward’s 2011 season, and how he is preparing for 2012. Here is a quote that may answer your question…

""I felt good the first month of the season," Heyward said. “The medicine kicked in. I was working out. I was feeling good. Obviously you had the adrenaline of coming into the season again, and I was having fun. I was off to a good first month. I hit one more homer than I had the previous year [in April] and I was hitting 20 points higher. In my mind, I was ready to go.”

When Heyward exited April hitting .263 with seven homers and a .879 OPS, there wasn’t much reason for concern. He batted .400 (14-for-35) with three homers in the final eight games of the month. But once he recorded just two hits in his first 29 at-bats in May, it became apparent something wasn’t right.

Heyward left a May 10 game against the Nationals after three at-bats, and then told media members that his shoulder had been bothering him since Spring Training. He played sparingly during the next two weeks and was placed on the disabled list on May 22. He was activated on June 15 after playing just two Minor League rehab games."

And the link to the entrie article from MLB.com: http://mlb.mlb.com/news/article.jsp?ymd=20111119&content_id=26010610&vkey=news_mlb&c_id=mlb