Raya, capped eight times for Spain, missed Arsenal's 5-1 home win over League One club Bolton Wanderers in the League Cup third round, with 16-year-old keeper Jack Porter getting his first start in the Spaniard's absence.
Raya, who permanently moved to the north London side from Brentford on a long-term contract in July, was seen leaving limping after the game following Arsenal's feisty 2-2 draw against Manchester City at the Etihad Stadium last weekend.
"We have to wait 24 hours to see if he is looking good or not that good. It's not risk, it is about a player being fit or available or not. We will make the decision tomorrow," Arteta told reporters on Friday.
Brazilian Neto, 35, could stand in for the injured Raya, having joined Arsenal from Bournemouth on a season-long loan in August.
Dutchman Jurrien Timber will be available to play against 15th-placed Leicester, Arteta said, adding he is hopeful about fellow defender Ben White's availability.
However, new midfield signing Mikel Merino continues to be sidelined with a shoulder injury.
"Tomorrow is too soon for (Merino), next week we will see. He had partial training today, he has been working so hard and looked really good. It is just about the healing of that bone and how mature that is to expose us to contact basically," Arteta said.
Despite missing Norwegian midfielder Martin Odegaard through an ankle injury, Arsenal are fourth in the Premier League with 11 points from five matches and Arteta said he was happy with the way his side have coped with the challenges.
"If you put them in that scenario before the start of the season, with the calendar we have, the fixtures we had and the three away games and how we got out of that, I would be very, very pleased I think," Arteta said.
"It's not only Martin, he is one of the players who has more impact on the team in many ways, but there were many others as well.
"The team has coped extremely well because we have an exceptional group, a lot of players are taking a different role in the leadership, in their role in the team and they embrace that challenge and I'm really happy for that."