Post workout drink on a low carb diet?

I would like to go on a low carb diet but still be able to drink the post workout drink that Biotest is coming out with. How would this afect my diet on training days. If for example it contains 50 grams of carbs then on the begining phases of a low carb diet, that drink would eat up my alloted amount of carbs for the day. Does it not matter that much when you are training and your muscles need the replenishment?
Thanks

Use a Targeted Ketogenic Diet (TKD).