Unai Emery hailed the positive impact of David Luiz as the summer signing's first Arsenal goal secured Premier League victory over Bournemouth.
Luiz, 32, joined from Chelsea in August and recorded his maiden goal and first clean sheet as the Gunners won 1-0 to move third in the table, just a point adrift of reigning champions Manchester City.
The shut-out was only the second time in 13 league games that Emery's side have stopped the opposition from scoring as Bournemouth lacked a cutting edge at the Emirates Stadium.
Luiz's glancing header from Nicolas Pepe's ninth-minute corner ended up settling the contest – with Emery praising the defender after the game.
"Yes, because he's very positive," he replied when asked if Luiz is popular in the dressing room.
"Every time he's speaking about positive things and helping young players. He came late into the squad but really, his commitment is very high with us, and his behaviour is too. Everybody is happy with that.
"We knew if we won, we'd go third. For our confidence and our way, it was important, but not feeling the pressure of that. Maybe in the second half, we were winning 1-0, maybe in some moments we felt that pressure."
Bournemouth offered very little in the first half but came into the game after the interval without truly testing Bernd Leno in the Arsenal goal.
"We were second best for long periods," admitted Cherries boss Eddie Howe.
"But you saw the other side in the second half, as bad as we were in the first half, we were good in the second.
"We dominated possession and deserved a point, we did well enough and had good enough chances.
"The conversation at half-time was that we needed to show ourselves more, have a bit more belief in our players.
"We were too reactive against Arsenal. You can't do that against good players.
"When we play well we're a match for anybody. Whenever we've played near to our best moments we've had a chance to win the game."