Strange. I'm much more positive about this than most of you.
He's a decent premier league centre back. Not great, but probably at least as good as Kolo these days. Very much in the 'it works' category.
Plus, if things go well and his hamstrings don't explode, he's young enough that it might be worth making permanent. Remember, this is a kid who was talked about as 'future England centre back' not long ago. And while that talk might have died down, those sorts of player (young starlets that need a second chance) are basically what Liverpool does these days. See: Coutinho, Sturridge, Sakho, etc. PS. All those examples are prime for 'if it didn't work with team X, doesn't mean it won't work with Team L'. Hell, we've got a few of those in the other direction too.
So, while he's probably going to be short term stop-gap, let's be positive.