The Gunners travel to Sheffield United on Monday for the first of seven matches in the space of three weeks.
Ozil has only featured twice this season and only once in the Premier League, but Emery has hinted that will change between now and the next international break.
Asked if the German World Cup winner has been made a scapegoat in the past, Arsenal's manager responded: "We live in the present.
"In this present we are looking for the best way to be competitive and to be a strong team, playing each match with our best quality of available skills and our best mentality.
"Mesut Ozil, for us, is important. Sometimes one player could be important playing or could be important being on the bench or could be important preparing for the next match. This is our mentality and this is the way we want to create with 25 players in the squad.
"I told you now for the last three weeks Mesut is working and improving and being better in training and if we need him, we are going use him because with his skills in some matches we are going to need him."
Ozil was a key player under Emery's predecessor Arsene Wenger and agreed a new three-and-a-half-year contract worth £350,000 a week with the club in January 2018.
The 31-year-old has seen his role in the team decrease since the Frenchman departed that summer and he was absent for several games last season.
During the current campaign, Ozil has often not even made Arsenal's bench and in an interview with The Athletic this week, the former Real Madrid playmaker admitted he was "disappointed" with his lack of game time.
He did reveal he is doing extra work with the club's fitness coach, though, and Emery urged players in his squad not to let frustration get the better of them when chances are limited.
"We need to be positive and also to learn from all the experience we are taking as a team, as a player and as a coach and to use that for the next step," Emery said.
"On Monday we prepare for the match. Then on Thursday we play in the Europa League against Vitoria.
"We have challenges every day, we have challenges when we are playing matches and we have them collectively.
"This is our mentality and really we can be frustrated with some moments in our past. We are in our present but that frustration is to be one step ahead and be positive and be consistent in our mentality and our work."
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