Llorente turned 30 this year, not that old for a football player ... If he took care of his body in the last few years,there are still 2 good seasons in him.
That's the conventional wisdom, yeah. But at the very top level, it doesn't hold true anymore (for strikers). They're being moved on and/or pushed out of the starting line-up before 30.
This is off the top of my head, running through the strikers around Europe's top clubs (which I hope, we all agree is what we're aiming to become apart of), so do correct me if I'm wrong. Apart from a few freaks of nature still making an impact in their late 30's in Italy (Totti and Klose), I can't think of anyone other than Zlatan making any kind of impact past 30. Tevez and Van Persie was getting there, but one's now moved to a smaller league and the other's about to. Oh and Llorente who's about to be moved on. Hopefully not to us though imo.