Cape Town - Arsenal captain Per Mertesacker was left impressed by the performance of Shkodran Mustafi in combination with Laurent Koscielny in the 3-0 derby win over Chelsea.
The pair snuffed out the threat of a dangerous Diego Costa, who has tormented the Gunners in recent seasons, and Mertesacker has praised the man who will likely succeed him in the starting XI.
The German centre-back used his match programme notes for the UEFA Champions League clash with Basel to praise the duo.
He wrote: "As a defender, I enjoyed watching how Laurent and Shkodran dealt with Diego Costa. I think the two of them will be a great pairing and what I find most impressive is how quickly they've developed their partnership.
"They really complement each other. When they needed to get really tight, they did. When they needed to be strong, they were. I think their partnership is getting better and better.
"On that front, we have a bright future because the defensive structure will be vital for this team moving forward."