Alexander Rossi, Indy 500 champ in '16, returning to Andretti Autosport

WATKINS GLEN, N.Y. -- Alexander Rossi will return to Andretti Autosport for the 2018 IndyCar Series season as part of a multiyear agreement announced Friday.

Rossi, who won the Indianapolis 500 as a rookie in 2016, has a 10-race sponsorship with Napa Auto Parts for his third season in the open-wheel series.

He declined to elaborate on the length of the contract after opening practice Friday at Watkins Glen International.

Rossi is seventh in points with two races left in the season. He is the third driver confirmed to drive for Andretti next year, joining Ryan Hunter-Reay and Marco Andretti.

Takuma Sato, this year's Indy 500 winner, is the lone Andretti driver to yet announce his plans for next year.