Kepa, 22, will see his current deal with Bilbao expire at the end of the season, and it has been reported that Real Madrid are interested in signing the highly-rated goalkeeper.
Ziganda, however, has insisted that he 'has no reason to be pessimistic' when it comes to the stopper's future.
"I have no reason to be pessimistic regarding Kepa's renewal," Ziganda told reporters. "I prefer to think positive thoughts rather than negative but this is just the situation, I see him every day and I know he is calm and enjoying himself at the club."
Kepa, who made 22 appearances for Spain's Under-21 team between 2013 and 2017, has featured in four of Bilbao's five La Liga matches at the start of the 2017-18 campaign.