I am very very much against selling him to Celtic for my own selfish reason of I fucking hate them, but this is just not true Grew. If he signs for them and makes the step up to the first team, he will be playing in the Europa League group stages at worst, and maybe the Champions League groups with a favourable draw.
His week in week out will stay the same but he'll get about 8 European games minimum and a lot more money for it.