The Blues skipper, who celebrated his 31st birthday on Friday, has helped the striker settle into the squad.
Robinson admitted: “He's been unbelievable and probably more so off it (the pitch) for me.
“He has a good blend of being serious when he needs to be serious and working hard.
“But still having that time to have a joke and laugh. So it's not all serious, because if you're serious 24/7, lads would be 'Come on'. “But since Thursday and Friday, you can feel it in the skipper that it's game mode."