Phillies officials had detected flaws in May's delivery, but were reluctant to make changes as the pitcher got off to a tremendous start, going 5-0, 2.40 in his first five starts at Double-A Reading.
May's ERA swelled beyond 6.00 in May, June and July. That provided instructors with a teaching opportunity.
"He got off to a great start," farm director Joe Jordan said.
"He had been elevating the ball but got away with it early in the
season. In May, June and early July, he had the same stuff. It was just
elevated and the hitters started getting to him. He's got great talent.
"He just needed to make some adjustments. When a guy is successful, you tend to stay out of his way. When he struggled, we saw an opportunity to do it."
Instructors tinkered with the positioning of May's hands and the speed and tempo of his delivery. "He fought it a little at first, but ultimately was very receptive," Jordan said.
Three of May's last five outings were quality starts. He allowed just two earned runs in 15 innings while striking out 18 and walking just three over two late-season starts. He finished 10-13, 4.87 in 28 starts with 151 strikeouts and 78 walks in 149 innings. Despite the ups and downs, Jordan saw real growth in the 23-year-old's performance.
"He finished the year really well," Jordan said. "He was a better pitcher than when the season started. He got his butt kicked a little, but he's better for it. It's part of the journey. He's healthy. He's got a great attitude. He's a great worker. He's fine."
• The Phillies added highly regarded Bart Braun to their pro scouting staff. He had previously been with the Rays.
• Darin Ruf, who led the minors with 38 homers at Double-A in 2012, had eight home runs and 15 RBIs in his first 50 at-bats for La Guaria in the Venezuelan League. Ruf hit three homers in the majors in September.