NEWS Oda drew older Luffy and Ace!

Unless he can't recognize him or doesn't read papers,he should know by now since I think Sabo was in the papers and is already known as 2nd in command of Revolutionaries.

 

where hmmmmm

 

was the face shown or not is the key
if yes then garp knows about him if not then he doesn't

 

first panel in 3rd row says "does that mean that this person here NEXT TO HIM is..." which implies there's Sabo's picture as well since the very next page shows Dragon's picture and first time Luffy seeing his father.

 

which does not confirm if face was shown or not

luffy can recognise sabo without seeing his face just by how he dresses since has already seen him

 

but it literally says NEXT TO HIM which implies Sabo and Dragon standing next to each other,what else would that mean...also the fact that Nami and Brook also wondered who that is clearly means it's whole Sabo's face,you wouldn't react OMG it's your brother if it's just a piece of clothes or just a hat of Sabo...