Mastiff pup has hematomas on her elbows from plopping on the hard floor?

my mastiff pup is 3 months old and has developed what is called hematomas on her front elbows from hitting the floor to hard. i bought her pillows to sleep on but she like the cold floor best. will this go away? is there more i can do? the vet says he can not drain them for fear of infection any one else have this problem with a mastiff????