"It looks like Christian probably won't play,'' coach Matt Rhule said. "I wouldn't say that's 100 percent, but it looks like he won't play.''
Rhule doesn't anticipate McCaffrey's injury, which he called an AC joint issue, to be season-ending.
McCaffrey is getting a second opinion on the injury suffered late in Sunday's 33-31 loss to Kansas City, a league source told ESPN.
The Panthers (3-6) will prepare for the Buccaneers (5-3) with Mike Davis, who replaced McCaffrey for six games when the NFL's highest-paid back was out with a high ankle sprain suffered in a Week 2 loss to the Bucs.
The shoulder injury occurred with 1:10 remaining when safety Daniel Sorensen slammed the Pro Bowl back to the ground near the sideline after a 1-yard catch.
McCaffrey had tests on Monday and is seeking another opinion Wednesday, making his future status week-to-week.
McCaffrey didn't miss a game during his first three NFL seasons, including last year, when he became the third player in league history to have 1,000 yards rushing and receiving in the same season. The Panthers rewarded him with a four-year, $64 million extension.