I haven't really followed this thread at all so forgive me if I'm repeating anyone. I suspect, perhaps, that I'm not.
I really don't have any problem with us signing Tuncay, provided the price is right, of course. He's a gifted footballer, he's a workhorse, and he has excellent awareness.
He strikes me as the sort of player who would benefit from being around quality footballers. I think his performances at international level would suggest that too. If he'd be happy to play a bit part role then I think he'd be a good addition. His industry and intelligence would make him an option in the event that Torres was injured as well.
I'm not saying we should pursue him with any vigour, but if plan A failed then we could do worse than Tuncay as plan B.