Reina believes his Liverpool teammate will still play an important role for Spain and has backed him to make a key contribution in the latter stages of the competition.
"Fernando is an important player for us," said Reina.
"It's always been like that and we cannot expect anything less than the best from him, so let's see if he can score in our next game.
"I don't know if he's 100 per cent fit. After two months out it's always difficult to come back and be 100 per cent straight away, but I am sure he will be later on at this World Cup."