"It's been frustrating, my injuries haven't been major but they've taken time to recover from," he told the club website.
"That's behind me now and I've been working hard over the summer.
"I have a good feeling for the season ahead, I want to push on and prove I can still play a part for the club."
A knee injury suffered against Derby at the start of the year ended the Wales Under-21 international's 2006/7.
"It was awful sitting on the sidelines while the club was struggling, but that's all behind us and there's a confident atmosphere here," said Crowell, who was at Southampton as a teenager and moved to the Racecourse in 2003.