Both forwards were substituted during Monday's 6-0 win at Sheffield United with Martinelli suffering a cut and Saka feeling unwell.
"We’re pretty positive that hopefully they can be part of that. But we’ll have to see," Arteta told reporters on Thursday.
Arsenal are third in the Premier League with 61 points, two points behind leaders Liverpool who face defending champions Manchester City, second in the table with 62 points, on Sunday.
Arteta said Arsenal, who have won seven league games in a row, needed to focus on maintaining their own momentum rather than on the results of their title rivals.
"We just have to focus on our game, try to win and then on Sunday it's a game that should be beautiful to watch for any supporter," he said.
"I will enjoy watching two of the best teams in Europe. I will sit there with my kids and enjoy the match."
Brentford, 15th with 26 points, put in a strong performance against Arsenal at home in November before Kai Havertz scored the winner for the visitors in the 89th minute.
"We know the demands we have and what Brentford will ask of us to win the game... we always suffer against Brentford," Arteta said.
