Arsenal boss Mikel Arteta says Nuno Tavares and Kieran Tierney can bring out the best from eachother.
Tavares is currently starting ahead of the squad.
Arteta said: "That's the level that we want to achieve, that in every position we have players that can perform at the highest level and can complement each other by giving you different qualities as well.
"Last year when we had an issue with Kieran, when he was out for a while, we had to invent and play players in that position, and that's something that obviously we want to eradicate as much as possible.
"That's why we made the decision that we made in the summer, to try to fill the gaps that we have and make the team stronger. It's only about that. Kieran hasn't played in a lot of games because he was still injured and in others, because once Nuno played and played well, I think he deserved the chance to continue playing."