Gyökeres. Havertz and Merino aren't serious starting options for elite sides, and there aren't many on this level who'd take them as strikers if you tried to sell them.
I reckon Havertz's best shot for playing time beyond as a backup striker is as an Ødegaard replacement. It'd mean we could let Eze settle on the left and finally get some consistency in the forward line too, which is what's been missing this season. We have formed great working partnerships in both defence (Gabriel and Saliba) and midfield (Rice and Zubimendi), whereas the attack just seems to consist of whoever's been eating their vegetables this particular week. I'm sure this is what Arteta meant when he said they can play together too: Havertz drops into that right midfield area naturally anyway.
I've always liked Havertz on a personal level but his lack of application means that he's a bit of an utility man, and that's exactly what he was signed as.