Goal says it is expected that the Brazilian club will turn down the offer.
The Gunners are keen to bolster their midfield ranks with Mohamed Elneny and Thomas Partey both currently injured.
Partey, 29, is currently suffering with a thigh problem while Elneny, 30, complained of hamstring pain after Saturday's 2-1 win against Fulham.
Further reports elsewhere suggest Palmeiras want £21.5m to sell the Brazilian midfielder.