The 28-year-old moved to the Emirates Stadium for a £45million fee at the start of last season.
O antigo Atletico Madrid player struggled to make an impact in Thursday’s 3-2 defeat at Manchester United a result which saw the Gunners miss out on the chance to break into the Liga Premiada top four.
Partey’s best display in an Arsenal shirt was during a victory at Old Trafford last season but he has struggled with injuries and consistency since he joined for a £45million fee in 2020.
Speaking ahead of their trip to Everton on Monday, Arteta said: “Thomas is a really important player in the team and obviously we’ve missed him for long periods since he joined.
“And that is not ideal but our energy is just to get the best out of him and how we will do that.
“The fact he had so many injuries has not been really helpful for him because he hasn’t found the platform first of all physically to be at his best and then he has had games where he has been more consistent than in others.
“We need him at his best and he can produce more. He knows we have to demand more.”
Hip and hamstring issues restricted Partey’s gamentime during the 2020-21 campaign and an ankle injury in pre-season saw him miss Arsenal’s first four fixtures of this term.
While the 28-year-old has been fit since September, the lack of a stable midfield partner has also contributed towards the Ghanaian’s mixed form with Granit Xhaka, Albert Sambi Lokonga, Mohamed Elneny and even Martin Odegaard playing alongside him in recent weeks.
“I don’t think it is related to the money, they have seen the quality and what he can provide on the pitch. We want to see that more and more often,” Arteta said of Partey’s critics.
“The fact we have to make some changes there doesn’t give him the consistency or a relationship and partnership with somebody to understand each other because of the injuries we have had but that is part of it so you have to adapt.”
With Xhaka not ready after his knee problem, Partey will again line up in midfield for the match away to Everton.
Victory for the Gunners would move them above rivals Spurs and into fifth but they would still be one point off the Champions League qualification spots.
West Ham currently occupy fourth but they are already six points off Chelsea in third while Liverpool and Manchester City are even further ahead to increase the likelihood that the teams battling to get into Europe’s elite competition are all aiming for one position.
Arteta admitted: “When you look at the table and at the teams (in the top three), they are really consistent and they win with big margins. They look superior to the rest.
"Então, it is clear there is a gap and I think for the rest there is a lot of balance and momentum actually, but we need to find the consistency with our results and go for it.”