After suiting up for on-field activities to start training camp, Buffalo Bills running back James Cook sat out Sunday's session.

When asked why he didn't practice, Cook responded, "Business," and gave the same answer when pressed about whether he'd return Monday, according to ESPN's Alaina Getzenberg. He reportedly didn't offer further explanation, repeating the word throughout the interview.

Cook, entering the final season of his rookie deal, has been vocal about his desire to receive a contract extension from the Bills. He'll earn a base salary of $5.2 million in 2025, according to Over The Cap.

"We've had talks. I'm never going to give up. I deserve what I want - what I need. It's going to eventually happen," Cook said in late July at training camp. "It's going to get done, wherever it happens at."

Buffalo declined to comment on Cook's absence from Sunday's practice, per Getzenberg.

Cook hinted in February that he'd like to earn $15 million per season after pinning a comment on an Instagram Live referencing the figure. A salary that size would make Cook the third-highest-paid rusher in the NFL.

The 26-year-old ran for 1,009 yards on 207 carries last season and led the league in rushing touchdowns with 16. He also hauled in 32 receptions for 258 receiving yards. The Bills drafted Cook in the second round in 2022 out of Georgia.