Takuma Sato's Andretti IndyCar deal expected before Christmas

Sato has raced in IndyCar since 2010, and with AJ Foyt Racing for the last four seasons.

But with Foyt's outfit switching to Chevrolet next year, and subsequently signing Carlos Munoz and Conor Daly, Sato is expected to join the Honda-powered Andretti outfit.

Sato is set to replace Munoz, with Ryan Hunter-Reay and Marco Andretti already confirmed as Andretti drivers, and Indy 500 winner Alexander Rossi staying in the Bryan Herta Autosport-affiliated entry.

"We'll make an announcement in due course about the fourth car but we feel pretty good about where we are at there," Andretti director Rob Edwards told Autosport.

"The good news is we are able to confirm everything that is happening in the next couple of weeks.

"We are well ahead of where we were last year where Alexander Rossi's deal came together very late the week before we went to Phoenix for the open test in the middle of February.

"The ability to plan, to get the right people in the right places those things are very hard to do when you aren't confirming the car line-up and the driver line-up until shortly before the season starts.

"I'm confident before we break for Christmas we'll have something to talk about for the fourth car, so it's another two to three weeks before we talk about the fourth car."

Sato, who will turn 40 before the 2017 season starts, has made 119 IndyCar starts, winning at Long Beach in 2013 with Foyt's outfit.

"He obviously has a lot of experience," Edwards said.

"We know he can be quick. Technically he has good feedback and good technical knowledge.

"All of those are potential benefits for us. We'll see how that plays out."