With the medical all done, it appears the soon-to-be free agent from Auxerre is a formality of processes away from signing with Arsene Wenger's side.
Gunners fans have been keeping a close eye on the Frenchman where possible, as after injury-hit seasons in France's Ligue 2, he's something of an unknown quantity.
We've run the rule over him at the U-20 World Cup, and it's clear Sanogo is no regular striker.
His big, hulking physique would have you believe—on paper—that he's a traditional target man, someone you can deliver the ball into and know it's safe.
And while he does have that in his locker given his natural size, he plays an odd, hybrid forward game: hanging on the shoulder of the defender whenever possible, working the channels and looking for balls over the top.
He's also happy to drop in and play the possession game, trusting his technical ability to work the ball from side to side.
We're not suggesting he's a complete forward, but he does appear to be willing to do every single job a striker should be able to do.
In his first game against Ghana, he spent the first 45 minutes dropping, if anything, too deep.
He interacted with his midfielders very well, with Jean-Christophe Bahebeck and Florian Thauvin thriving off his presence, playing one-twos and finding space in behind the full-backs.
Geoffrey Kondogbia, who was playing a hybrid flat central midfield/No. 10 role, used him as a give-and-go on his barnstorming runs forward.
All that was fantastic, but he failed to get into the box and actually provide a goalscoring presence.
In the second half, he hit the post from a corner, though, and gradually crept into the game. Kondogbia surged forward, played the ball into Sanogo's feet, and a fantastic touch wide of his marker later, he was slotting home between the goalkeeper's legs.
In France's second game against the U.S., Sanogo scored a weak penalty to take his tally to two in two.
Les Bleus, as a whole, have blown hot and cold throughout the tournament already, and Sanogo is consistent with this.
He's nowhere near the finished product, but crucially, he has a footballing brain that's advanced beyond its years. Injuries have slowed his development, but he'll always have a natural physical advantage that allows him to dominate those his age.
French Football Weekly's Le 50 scouted Sanogo and drew the following conclusion:
Will his injuries clear up and allow him to play full seasons of regular football? And has his technique survived these long periods of inactivity at such an important stage of his development?
A yes to both those questions, plus a little bit of luck, could add up to a superstar.
A risk worth taking on a free, if you're Wenger.