The Germany international is recovering from a knee injury picked up before the FA Cup final.
"It is certainly looking good at the moment," he told Stoke City Player. "I have been doing loads of running and gym work at the training ground and hopefully it will put me in a position where I am ready to get underway straight away.
"There are still a couple of weeks left until pre-season starts so I will keep doing my work, because it is hugely important not to be playing catch up with them once pre-season gets underway.
"Pre-season is a very important time for us, and it is actually a time of the season I do enjoy. It's a testing time but I enjoy the challenge of it. I'm not sure I will still be saying that when we are doing the hills in Austria though.
He added: "It's the time where we can all do the ground work to ensure that we will be ready for the season. Our fitness levels last season undoubtedly helped us, and it is in those final few weeks of the season that you really feel the benefits of pre-season."