Pretty odd for a manager to ask if you want to take a holiday for a specific week, generally that's the sort of thing you choose yourself - like a full week is quite of lot of someone's annual holidays, I wouldn't just randomly use it because a manager suggested it, paid or not. If anything I try and always keep a week saved up in case of unexpected stuff.
As above did you make a specific holiday request for this period or was it just on your managers word? Either way I think they're the one you need to initially approach.