Free safety Kendrick Lewis injured his shoulder in Saturday's loss and will miss an undetermined amount of time.
Chiefs coach Romeo Crennel then found out that the NFL has suspended linebacker Tamba Hali for the season opener against the Falcons.
Hali violated the NFL's substance abuse policy.
He will also be fined one additional game check.
Hali will be able to practice with the team and play in the two remaining exhibition games.
The one game suspension means that Hali was not suspended for using performance enhancing drugs.
It was for illegal use of other drugs or alcohol.
"There's a consequence to be paid for it," said Chiefs coach Romeo Crennel. "And Tamba will pay the consequence. We are disappointed. We're disappointed for him, we're disappointed for the team. Tamba is a guy who's very prideful. He's been a very good team member for this team. And I think the team will rally around him and support him."