The midfielder has emerged as one of the Premier League's standout performers this season.
Arteta faced a long list of questions in his pre-match briefing, but the focus repeatedly returned to Zubimendi.
The Arsenal manager refused to rank the Spain international against other top midfielders, yet he stressed that the 26-year-old's impact has already transformed the way the Gunners operate.
"My players are the best," Arteta said. "To compare him with other players, I don't think it is fair. Each player has his own qualities.
"The impact of Zubi on the team is unquestionable. What he is doing so early in his career here is very impressive.
"We need players operating at that level, playing consistently and helping the team."
Zubimendi arrived from Real Sociedad in the summer after months of speculation and interest from several major European clubs. Arsenal ultimately secured the deal despite reports that Real Madrid could attempt a late move. The transfer, worth around sixty-two million pounds, has already proved excellent value.
Since joining, Zubimendi has been a revelation. He has completed eighty-nine per cent of his passes in the league and is averaging four duels won and two tackles per match. He has also chipped in with three recoveries and two clearances per outing, offering Arsenal a calm, assured presence alongside Declan Rice.
The Spaniard has started every Premier League match this season, except the win over West Ham United when he replaced the injured Martin Odegaard after half an hour. His consistency and control have been central to Arsenal's strong start to the campaign.
Zubimendi is expected to anchor the midfield again on Sunday, with Arteta viewing him as a key figure in winning the derby's decisive midfield contest.
"He is going to be very positive for the team and the results of the team," Arteta has said, an assessment Arsenal supporters will hope rings true in one of their biggest matches of the season.