Christine Ohuruogu says she was "surprised" to be called up into the British team for the World Championships in Osaka this month.
Ohuruogu says she feels in good shape for Osaka
The 400m runner finished a one-year ban for missing drugs tests on Monday, a day before the team was announced.
"I have to admit I was surprised I'd been called up to the squad," she said.
"I didn't know what the selectors were wanting. I had the qualifying mark from 2006 but it's always good to get the required time on the eve of an event."
The 23-year-old has appealed against a lifetime ban from the Olympics, as is mandatory under British Olympic Association rules for any athlete convicted of a doping offence.
But in an interview with BBC Sport, she said she would not dwell on that issue as she prepared for Osaka.
"The Olympics is my dream but it's something that's not in my hands. I only deal with what I can control," she said.
Ohuruogu said she had found it hard to deal with the doping ban.
"The whole issue has been devastating and I was unprepared for what happened," Ohuruogu told BBC Sport.
"You obviously look back and wish you had done things differently."
The Commonwealth 400m champion missed three out-of-competition drugs tests in 18 months and as a consequence received a one-year ban.
I felt I wasn't being supported by the system and that it was trying to catch me out
Ohuruogu said at the time she would need to reconsider whether she had a future in the sport.
But following her selection in the team for Osaka 2007, the former netball player said those negative thoughts were soon erased from her mind.
"There were times when I thought everyone was against me," she added.
"I felt I wasn't being supported by the system and that it was trying to catch me out. But it's the same for everyone and I had to learn to move on.
"When things go wrong you're going to feel upset and wish it never happened. But it's hard to work when you're frustrated, angry and unhappy."
Ohuruogu said she was pleased with her current state of fitness ahead of the World Championships later this month, where she is set to compete in the individual 400m and the 4x400m relay.
"It will be hard now and I'm probably at a huge disadvantage because I haven't raced. But I've been training well, I feel physically and mentally strong and I'm prepared to take the challenge now.