You could just said "I haven't seen him at all". No need to mask it with irrelevant stats.
He is 19 years old. For all you know (given you have seen nothing him), he could be as talented as Martial. If that were the case, we still shouldn't him for 18-20 million pounds? As
@lysglimt has posted, strikers don't tend to get a goal every other game in their teens. Check out Rooney's record for Everton before he joined us as an 18 year old.
For a teenager, it's mostly about the natural ability/talent, unless the strikers is evidently rubbish in front of goal.