The Swiss as joined the Hammers from Lazio in 2008 and just recently returned from a knee injury that kept him out since March.
The 24-year-old’s contract with West Ham expires in 2013.
“I know that the people at West Ham have confidence in me,” he said. “Maybe one day I will play for a bigger club than them.
“However, in order for me to do so, I will need to be at the peak of my abilities.
“I just play my football from day to day.
“There is no point in me talking about my medium-term future when I don’t know what might happen tomorrow.”