Williams has been involved in two fights during the pre-season, including one with teammate Riley Cooper this week.
"I know after yesterday, Cary understands that we need him on the football field, not to be hot-headed at times," Vick told CSN Philadelphia.
"We know he's a guy who's very into his work and what we do, and he can't be high-strung all the time.
"He's got to stay even-keel like everybody else, just out of respect for the game more than anything."
Philadelphia open their season against the Washington Redskins on Monday.