Belgium boss Marc Wilmots has played down concerns over Romelu Lukaku's fitness for the World Cup, describing his injury as "not too bad".
The striker limped off in Belgium's 1-0 win over Tunisia after injuring his right ankle in a challenge with Bilel Mohsni.
Lukaku left the pitch in second-half stoppage time, but Wilmots has claimed that the Chelsea forward has suffered a "severe sprain" at worst, which will not rule him out of the tournament in Brazil.
"Romelu has problems walking," Wilmots told reporters. "His injury seems at first sight not too bad, the doctors told me.
"This is preliminary to a severe sprain but we will obviously do additional tests on Sunday."
Lukaku has earned 29 caps for Belgium.