The 18 year-old defender told arsenal.com: "Havard [Nordtveit] has come in. He is done so well since he got here. He came into a unit that had played together for some time, but was able to fit in without a worry. He is great on the ball, strong with his body and can read the game.
"You could see that he has impressed the manager because he was on the bench at Sunderland.
"He brings competition for places and that can only help. If there is no competition you might slip and become too relaxed, thinking that it is your place. With players coming in it keeps you on your toes and we all keep trying to better ourselves."