With his contract dispute ongoing, Buffalo Bills running back James Cook showed up for Sunday's mandatory practice but did not participate. Instead, the 25-year-old stood off to the side and spent a short amount of time on an exercise bike.

James Cook is seeking a new contract with the Buffalo Bills. He sat out practice Sunday as he negotiates with the franchise.

James Cook didn't participate in practice Sunday in what could be the next step in escalating his bid to extend the final year of his contract.