Have you met the puppy? Our boy, Leif, was one of the last 2 male puppies left from a 9 pup litter (there were 2 other females left as well). He was significantly smaller than the other male, but we liked his personality a lot more than the other one. We were concerned about him being so small too. However, because of the litter size, we thought he'll catch up when he doesn't have to compete for food. He's from a reputable breeder, so we weren't concern about the quality of the sire and dam (we also met them). He was only 14 lbs when we took him home.
He is almost a year old now and weight 73 lbs, great temperament, good looking and very smart. We could not have asked for a better pick! I think you'll be fine with your pick too. Good luck! and don't forget to post pictures. We love seeing floofy puppies!