"David came back in and performed well," Cahill said. "Andreas is a younger version of him if you like. I feel like David can offer Andreas a lot of help in his progression. He has been there and done it at the top, top level, he has won many trophies.
"David is a very experienced defender and Andreas' attributes are very similar. I feel that he (Luiz) can advise him tremendously and he has done up until now."