Smith, a three-time Pro Bowl selection, will continue to practice when training camp resumes Monday and will be allowed to participate in preseason games, coach John Fox said Saturday.
Lucas, who left the practice field at Wofford College on Friday with ice over his left eye, has a broken nose, Fox said. Smith was kicked out of practice and sent back to Charlotte.
"What [Smith] did was wrong and we take very serious and he is being punished severely for it," Fox said.
The melee came after both players had taken off their helmets in a break for starters during a special teams drill. It was unclear what provoked the fight. While the two have routinely jawed at each other in practice since Lucas signed with Carolina in 2005, they've never come to blows in view of reporters.
The suspension will cost Smith more than $205,000, a fraction of his base salary. Fox also seemed to issue a stern warning toward Smith and his future actions.
"He is still ours and he will have conditions," Fox said. "He knows what those are and we will move forward."
Lucas, who was not suspended, did not practice Saturday at Fan Fest and is listed as day-to-day. He showed up in the locker room Saturday morning unexpectedly and was mobbed by teammates, according to quarterback Jake Delhomme.
Delhomme said he was proud of Lucas for coming.
"Ken got overwhelmed with every single player coming up to him and telling him hello," Delhomme said. "I think it was great that he came out today. A lesser person would not have come out. But he did. And we can't wait to get him back."
Delhomme said he hasn't spoken with Smith, but has exchanged text messages.
"Steve will be back with us," Delhomme said. "I know he's extremely remorseful and he understands. But if we want to be a good football team we have to win without him."
Smith will miss the season opener at San Diego on Sept. 7 and the home opener the following Sunday against Chicago. He will not face any additional punishment from the league.