Costa Rica goalkeeper Keylor Navas has sat out a training session because of a shoulder injury.
However, a team doctor said he should be fit to face the Netherlands in their World Cup quarter-final on Saturday.
"We have to be careful and keep an eye on that," doctor Erick Sanchez told reporters.
"We chose to be careful with him and let him rest so he can play on Saturday."
Costa Rica beat Greece on penalties in their last match, with Navas blocking the final Greek spot-kick with a brilliant one-handed save.
They face the Dutch in Salvador in an attempt to make the semi-finals for the first time.