Mainz striker Sami Allagui spent a night in hospital in Frankfurt after falling ill while on international duty.
The Tunisian turned out for his country in a 0-0 draw against Malawi in an Africa Cup of Nations qualifying match last Saturday.
Allagui then had to be admitted to hospital due to blood circulation problems, but he is still expected to be fit for this weekend's match between Mainz and Hoffenheim.
"The forward had not eaten or drunk enough and he suffered from circulation problems," said Mainz in a statement.
Allagui has already scored two goals this season for Mainz, who currently sit in seventh place in the Bundesliga after four matches.