He's still fourth choice, just that one of those choices is unavailable.
If a choice isn't available, is it really a choice?
That's my line of thinking. He is now third choice as Coloccini is injured.
Your line of thinking is wrong though. Coloccini doesn't cease to exist just because he is injured, that's the whole point in having a more than one player for each position, sometimes you might be forced to play your fourth choice, that doesn't mean he's moved above the third choice.
Anyway, what a shit argument