Germans often use the filler word (or particle) doch to emphasize the hope expressed by this use of the future perfect. Use it in these cases to sound like a real pro!
Peter ist nicht zur Arbeit gekommen. Er wird doch hoffentlich nicht wieder krank geworden sein!
Peter didn’t come to work. Hopefully he hasn’t gotten sick again!
To learn more about filler words in German, read our article on German particles.