McMillan didn't practice Monday or Tuesday after banging a knee "a couple days ago," Scott Smith of the Buccaneers' official site reports.
McMillan was wearing a sleeve on his left calf during practice Tuesday, but it sounds like the issue that's kept him out of practice is related to one of his knees. Head coach Todd Bowles suggested the Bucs are just being careful with McMillan, so it doesn't appear he's dealing with a long-term issue.