The drug found in Collier's system when he was tested late last season was Adderall, an amphetamine used for attention deficit hyperactivity disorder, or ADHD.
Collier said he has had trouble paying attention since his kindergarten days in Southern California, but his mother did not want him taking any sort of medication for the problem at a young age.
Instead, he struggled in school.
"It was always tough in school," he said. "I was in special classes and I can remember being laughed at a couple times when I had to leave class because I wasn't paying attention. People would say, 'You do the easy work or whatever.' I wanted to be up to the same pace as everybody else, but sometimes I'd have to leave the classroom or do separate work that was the same subject, but a little slower pace.
"I just wanted to be able to be like everybody else. It has always been an issue for me to even talk about."
That's part of the reason Collier spent the first 50 games of this season counting down the days until he could leave extended spring training and join the Clearwater team.
Concentration had been a big problem for Collier during his first four professional seasons.
"Every now and then I can definitely feel it at the plate, but it's more so in the field and on the bases," Collier said. "The bases, I had a history of kind of not paying attention a whole lot. I'd be on second base and a ball would be hit to my right and I'd go to third."
Collier thought Adderall would help his problem, but he never told anybody in the organization he felt he needed it, and it is a banned substance by Major League Baseball unless medical approval is obtained by a player.
"I wasn't sure how to come out about it and let them know that I do need help," Collier said. "I needed to communicate more. It should have been brought up a long time ago."
Collier found out he failed the drug test near the end of his 2011 season at Lakewood. It had been a decent comeback year for the Phillies' second overall pick in the 2008 draft after he missed the entire 2010 season while recovering from wrist surgery.
"It was kind of tough to hear," Collier said. "I didn't really know what I was going to have to go through."
Collier said God, family, and his friends, particularly his Clearwater teammates, helped him get through the 50-day suspension, but he admitted it was not easy.
"It was kind of tough seeing those guys play and having such a good time and I had to get up early and go work out in extended spring training," Collier said.
He also received counseling from Dickie Noles, the former Phillies pitcher who is now the team's employee assistance professional.
"He helped a lot," Collier said. "He told me what I'd be going through in extended spring training and he told me to stay confident and continue to believe in myself. He called and checked up on me a lot. He made sure I was in good spirits."
Collier said Noles was also trying to help him go through the proper channels to be able to use Adderall again to help with his ADHD, but he said it was more difficult once you fail a drug test.
For now, Collier is doing just fine without the medication.
Through his first 14 games with the Threshers, he batted .339 (19 for 56) with five doubles, a home run, and 11 RBIs.
"It's great," Collier said. "I just wanted to get off to a good start after what I've been through and I just tried to keep a positive mind-set. I feel like I did before when I was coming off an injury. I'm really hungry and ready to show what I can do. I just want to prove I can play this game at a high level."
Contact Bob Brookover at email@example.com
or on Twitter @brookob.