Arsenal manager Mikel Arteta was delighted with the impact of defender Gabriel.
The Gunners produced a battling display to defeat Sheffield United at home, picking up three more valuable Premier League points.
And Arteta admitted his team had to do a lot of defending, which Gabriel helped with significantly.
He told the club's website: "I am very impressed because I've always said that in this league, in this country, one of the most difficult positions to play is as a centre-back because you get challenged and exposed many times and tested many, many times.
"I saw from the first day, he has a lot of personality, he has big courage to play and he's not impressed by anything. He's very secure, very stable mentally as well throughout the game and I think he has the physical and technical attributes to adapt really well to the league.
"That's why we signed him, but credit to him because to do it in this short space of time, I think that's a big thing.
"I think for him to be stable, for him to perform, he needs the right structure around him and the right organisation. I think we are getting much better at that. I am seeing a lot defenders involved saying it's something we had to improve. Yes, it's made us a more solid team.
"As you can see he doesn't get exposed in many open spaces. This is more about the function and the structure of the team and that's going to help them.
"The better our process is with the ball, the better we progress into the final third, [the better] we're going to help our strikers so the defence is the same."
