After the Aouar deal failed to materialise, attention quickly switched to Partey, with the move being confirmed on deadline day.
The London side triggered his £45m release clause but still had to convince Partey to leave Atletico, which they managed after Arteta and director Edu talked to the player.
"Arteta was very important [for the move]," he said.
"Him and Edu told me about their plans and it was so exciting, so I had to accept it.
"[The manager] has seen me play and knows what I can bring to the team. I think he watched me at Atletico and wants me to bring the same to this team.
"I think I have to be quick [to adapt] and learn everything as fast as I can. I have to do everything I have to do in training and make him see me and that I'm ready to play for him.
"It's a great challenge. I want to experience new challenges. I'm ready to give it my all and help the club get back to where it belongs."
"It's something that will be difficult," he said when asked about title aspirations.
"But we will be working towards it. I think we are ready. We have to go all out to try and achieve."
Arsenal have made a solid start to the 2020/21 Premier League season, as although they were defeated 2-0 by Liverpool, they have won their other three matches versus Fulham, West Ham, and Sheffield United.
This weekend, they travel to the Emirates to take on Man City.