"Things haven't gone as well as I had hoped but I think I've made a contribution in my 18 months," said Kewell
"I'm my own biggest critic and I don't need people to tell me when I'm playing well and when I'm not because I know and tell myself.
"I don't think I hide from my bad games but, at the end of the day, everyone has them from time to time."
The Aussie forward has suffered niggling injuries in the last 12 months, but is not making excuses.
"I'm still feeling the injury to my abductor at the moment," he added. "It's giving me a bit of grief and I could probably have done with a little bit longer to get over it completely.
"But because of everything we've got on our plate I've had to step right back into it."
"I'm not a player who has been injured regularly but I can't remember the last time I went into a game not feeling a strain somewhere on my body.
"It's not just me. I'd be surprised if anyone goes out 100 per cent fit because there are always knocks and niggles."