Ferrari president Sergio Marchionne has ruled out Fernando Alonso returning to his Formula 1 team.
However speculation of Verstappen joining the Scuderia is up in the air Marchionne said, "As for Verstappen we have not signed anything. Before the end of the year, you'll know."
Marchionne has already urged Raikkonen to raise his game over the remainder of the season if he is to keep his seat for 2018.
"Kimi has got to show a higher level of commitment to the process," said Marchionne.
"There are days when I think he's a bit of a laggard, but we'll see."