I can't see this fight going the distance nor Jiri taking this to a ground fight, but both will have some advantage which could play out to end the fight and most probably it will be over in round 2.
Jiri being inactive and coming out from shoulder surgery and Pereira being in his favored weight class, he can certainly just fight toe to toe with Jiri and will KO Jiri by head kick or a big swing to the chin. Or Pereira could blackout with just a straight punch being so open whenever he kicks.
That's why they are a good match-up to have this weekend and it will not take long as you said because both are good finishers in their own way. But I think Pereira is the underdog here because of his performance in his last fight but that's understandable since he came from a loss to Adesanya which was not really good for him since he used to bully that guy.