I don't know how true this is... But if it is then it would be the reasonable thing to do for Sporting. Because there is no way they are selling him for a price like 85 million pounds (~100 million euros).
His market value is 75 million euros according to Transfermarkt. They should be more reasonable with the price. He is a great striker but expecting 100 million for him is too exaggerated.
When I first saw the report that Sporting's asking price for Viktor Gyokeres was above 85 million pounds, I frowned at it because o thought it was too outrageous for a player of his status. Of a truth, we know he's a very prolific striker but that initial price i think was above what I thought of his value. Now that Sporting have reduced it to less than 60 million, Arsenal must act fast if they truly want to to be competitive next season. I personally think that they're not considered as a strong contender for any competition this season because of lack of striker. Viktor Gyokeres would be a perfect man for Mikel Arteta's team ahead of next season.