McCaffrey is expected to miss four to six weeks after suffering a high ankle sprain during Sunday's loss at Tampa Bay, but he said Monday that he hoped to return faster than that.
"They say four to six weeks [to recover]," he said Monday. "Well, that's a challenge to me. Hopefully, I'll get back a lot earlier than this."
Coach Matt Rhule said the Panthers decided to use McCaffrey's roster spot for another player. He didn't expand on who that player might be but added that he was satisfied with the three backs -- Mike Davis, Trenton Cannon and Reggie Bonnafon (practice squad) -- on the roster.
"He's still around the team," Rhule said of McCaffrey. "He's still here. He's still in meetings. He's out for at least three weeks, so we decided to use his roster spot. How long it takes, we'll go from there."
The Panthers made McCaffrey the NFL's highest-paid running back during the offseason with a four-year, $64 million extension that averages $16 million per year. Last year, he became the third player in NFL history to have 1,000 yards rushing and 1,000 yards receiving in the same season.
ESPN's David Newton contributed to this report.