On Scrum, the team commits to deliver some set of functionality by the end of each sprint and the whole team is accountable for what they engaged to deliver. Missing a team member, even if temporarily can affect the whole sprint and if effects are considerable, the Scrum Master will recommend cancelling the sprint or removing stories to be delivered. Product Owners must be aware of how Scrum works and understand the importance of keeping the team focused on their tasks.
Team members need to be completely transparent with the PO, the SM, and the rest of the team. Even if someone offers them a free trip to Iceland, they still need to ask permission from the Scrum Master.