The experienced central defender could be dropped for the Owls' clash against Coventry next weekend after some disappointing displays in recent weeks, but the former Cardiff man has vowed to prove his worth.
Purse told the club's official website: "When I came into the club at the beginning of the season, it was said that I would be the person to sort the defence out and I probably haven't lived up to everybody's expectation.
"I'm big enough to say that and the only way to rectify it is hard work - as I have always done throughout my career - and hopefully there will be a chance for me to put it right against Coventry.
"If not, then I will continue to work hard until the next chance comes, hopefully sooner rather than later. Nobody is 'undroppable', nobody is bigger than the side and nobody is bigger than the football club, it's as simple as that.
"I just hope I will be in the side against Coventry but if not, I will take it on the chin and then it's how you bounce back, it's a decision that the gaffer has to make."