And speaking after playing 90 minutes in the loss to England on Monday, Alonso revealed the new deal was imminent.
"I am very calm and very happy at Chelsea," Alonso told AS.
"The club must also be happy with me because, although I still have two years left on my contract, they have offered me an extension."
"We are talking about it and the talks to renew are already advanced. If everything goes well, I think I will renew before the end of this month - in the coming days."