The New Zealand international had to limp out of Thursday's UEFA Cup defeat at Larissa, and initial estimates suggested he could be sidelined for a month.
But Hughes told Blackburn's official website : "He's a little bit sore, but it's similar to when he had an episode concerning his hamstring at Bolton last year.
"I think he missed something like ten or 15 days and he felt similar pain that he's having now.
"It isn't the actual hamstring as such - it's not a muscle injury. It's just a pain that he gets when the scar tissue releases.
"We think that's what's happening and, if that's the case, then the prognosis is probably better than we originally thought."