On May 22, Reading had just completed a day game against visiting New Hampshire when a massive hailstorm blew through the area.
Biddle was pelted by hail and suffered a concussion.
"My head was bleeding, and in the back of my head was a huge bump," Biddle recalled.
He missed a start, then passed his concussion tests and returned to the mound on May 31. Even when he returned, Biddle didn't feel everything was right.
"I didn't have that extra bit," he said. "My thing is, when the bases are loaded, I can make a push and get out of the situation, but it was kind of difficult for me to get there [competing] and I was confused."
Finally, after allowing 10 earned runs in three innings June 23 against the Binghamton Mets, Biddle was sent down to the Phillies' minor-league complex to regroup.
"When I got down there, the doctor said that my concussion was still affecting me and there were post-concussion symptoms," said Biddle, who is 3-9 with a 5.03 ERA in 15 starts this season for Reading.
So he took his time, regained his health, and began working on his craft, including his mechanics. Biddle, who admits to putting plenty of pressure on himself, also had several conversations with former Phillies righthander Roy Halladay.
While with Toronto, Halladay spent parts of three seasons in the majors before he was sent down at the beginning of the 2001 season to single-A Dunedin to work on his mechanics and mental approach to pitching.
Halladay certainly learned from the assignment. Beginning in 2002, he started a full decade of dominance, including a 40-16 record in his first two seasons with the Phillies, in 2010 and '11.
"I talked to him a couple of times, and he is pretty awesome and he knows a whole lot about kind of losing your way on the mound and regaining it," Biddle said.
Halladay, returning to Citizens Bank Park for alumni weekend on Friday, saw definite similarities between what he and Biddle experienced as young players.
"It is just exactly like me," Halladay said.
Halladay talked to Biddle about having a singular focus.
"He is feeling better, but the hard thing for people to realize is what they can and can't control and they get caught up in that a lot," Halladay said. "Having him understand what is in his control, I think, has helped him."
Biddle worked on his game in Clearwater and returned to pitch two innings for the Gulf Coast League Phillies on July 26, allowing one earned run in two innings.
Wednesday against Daytona, he struck out five and walked one. He threw 64 pitches, 45 for strikes.
"I saw a really tough breaking pitch, and he was attacking hitters," Clearwater manager Nelson Prada said by phone.
Prada added that Biddle's fastball stayed in the 90-92-m.p.h. range.
Biddle, who will turn 23 in October, will make his next start for Clearwater on Monday at Brevard County.
"I am just taking things one game at a time," he said.
After that game, the Phillies will reassess his situation.
"If things continue in a positive way like they have, then I think it's realistic he could be pitching back up north [for Reading] before the end of the season," said Joe Jordan, the Phillies' director of player development.
More importantly, Biddle says he feels fine.
"It was nice to be back pitching in a competitive environment and feeling like myself," Biddle said. "I am not a results-based kind of guy, but it was nice to have good results."
And there was an added bonus.
"I felt like myself again," he said. "I am enjoying myself out there."