Michael Ballack is determined to make himself undroppable at Chelsea next season.

The 30-year-old has set himself the target of becoming the irreplaceable midfielder for his club side, as he already is for his country.

"I have had to work for the position which was always mine for Bayern and the national team," Ballack said. "I now want to play this role with Chelsea. I still have not earned the recognition which I would like at Chelsea."