Clearly intentional, it's not exactly a secret that Barkley is part Nigerian, it's one of those "interesting facts" that you hear all the time about footballers. Also, if someone was picking out an animal to compare someone to for the lack of understanding in their eyes, a gorilla would probably the last animal you would think of, they have incredibly emotive eyes. He's just tried to sneak it through knowing he can feign ignorance and a certain section of twats will defend him.
To be honest, the racist angle isn't even the worst part of that "article". It's just a completely unprovoked attack on Barkley and all of Liverpool, from a man who fucking loves doing that. The biggest sham is that the Sun suspended him, as if it was just him who put that article in their paper and it wasn't overseen and given the all clear by a series of editors. The Sun really is the scummiest of scummy newspapers, I genuinely don't know why anyone reads it.