text: In 2001 , Michael Schumacher made a one-off return to karts and competed against Hamilton along with other future F1 drivers Vitantonio Liuzzi and Nico Rosberg .
simplified: In 2001 , Michael Schumacher made a one-time return to karts and competed against Hamilton along with other future F1 drivers Vitantonio Liuzzi and Nico Rosberg .