Detroit Lions wide receiver Ryan Broyles has admitted that coming back from two bouts of ACL surgery in less than three years has been one of the biggest challenges of his life.

Broyles has had a torrid time with injuries of late, although earlier this summer he claimed that he would be fit to play in his side's opening match of the 2013 regular season.

However, with less than a week now to go before the new season kicks off, the 25-year-old admitted that his body is still unpredictable as to how it will react in training.

"Your body shows up some days and some days it doesn't," Broyles told the Lions' official website.

"This has been one of the most challenging things of my life, coming off two ACLs. I'm out here trying to compete at a high level."

The Lions will face the Minnesota Vikings in their opening game of the upcoming season.