The 20-year old is expected to complete his move imminently, and reports from France suggest he may have already passed a medical.
But it appears the Ligue 2 club's hopes of taking the striker back on loan will be dashed, after Arsene Wenger told them he plans on making the youngster part of his first team plans next season.
After meeting with the Arsenal boss on Monday, Auxerre chairman Guy Cotret told a French radio station: "He will only loan him back to us if he considers the player is not ready to join his team after the preseason preparations.
"Otherwise he will not loan him," he added.
Sanogo is expected to sign a four-year contract with the North London club after turning down a new deal two-year deal in France.
The France Under-21 international has scored eight goals in seven Ligue 2 games this season, with four of his appearances coming from the substitutes' bench.