Timber, who suffered an anterior cruciate ligament (ACL) injury in August, played half a game for Arsenal's Under-21 side on Monday.
"We’re going to have to make that decision (about Timber) tomorrow after a training session," Arteta told reporters on Friday. "I don’t know if this is going to come to soon for him, but he’s very close."
Arteta said having so many players available for selection was a "good headache" to have.
"You feel for the players, because I see how much they want it and how much everyone wants to start and contribute to the team," he said. "They are fully ready to come on the pitch... the spirit is so good."
Arsenal, with 77 points from 34 matches, are just one point ahead of defending champions Manchester City who have a game in hand.
"There is one thing to do in this situation. Compete, compete, complete," Arteta said.
"It's a really good sign because we know what we are going to have to do to win it and we have to raise the bar every day in training to match that."
Arteta said fifth-placed Spurs' performance under manager Ange Postecoglou was impressive but Arsenal would be ready for the challenge.
"We have had a bit of time to recover... and I'm sure their team is going to be fully ready to go again on Sunday," he said.
