"It doesn't really work like this," Arteta said. "So yes, we lost the game, obviously not happy about it. Certain players need to get more minutes and rhythm, which is going to be really helpful, especially certain parts of the game. Tomorrow, finally, everybody is back."
The result means Arsenal have now lost back-to-back pre-season matches, following a defeat to Real Betis in midweek, though Arteta played down suggestions supporters should be alarmed.
"We lost two actually, Spurs and Villarreal in a row [last year]," he said, recalling a similar blip 12 months ago.
"I think it has to hurt when you lose a football match, it has to hurt when it is a friendly match. But yes, we know where we are. We know that we are missing still a lot of players and some players that haven't had enough training."
Arteta also discussed the club's marquee signing of the week, with Bruno Guimaraes arriving from Newcastle United in a deal reported to be worth around £75m.
"I'm delighted to have him," Arteta said. "We see very clearly, especially the energy that he brought immediately to the training ground, the hunger, the desire to come here and create a big history at the club. And that's the ambition that we need."
Asked whether Guimaraes could be described as a warrior, he added: "I think he's proved that. I think not many people would question associating him with that word."
On what the Brazilian offers on the pitch, Arteta said: "Versatility to play in two different positions in relation to what the opponent or we do. A player who obviously has tremendous timing and intuition to win the ball back and progress play very, very fast. He's a player that is very comfortable putting people through, pulling between the lines, pulling behind. And then he's a goal threat. He's got a smell and a really good timing to get in the box."
There was less certainty over the returns of William Saliba and Jurrien Timber, both absent again on Sunday.
"Jurrien is progressing really well. He's on the pitch, he's doing quite a lot right now, but it's still weeks away," Arteta said. "William Saliba is in rest mode at the moment for two weeks. He had to do almost nothing, an aggravated injury, so it's going to take some time to heal."
Arteta confirmed several World Cup returnees, including Bukayo Saka and David Raya, were already back in training a day earlier than expected, with the full squad due to report on Monday, though their varying fitness levels would shape how Arsenal manage the opening weeks of the season: "This is part of the preparation that, if we don't see the result right now, makes sure that we see it in a week when we start to compete for the major trophies."