The 37-year-old Swiss-born Frenchman shared the latest update via social media, with a statement that also acknowledged his departure from the team, which recently became known as Andretti Global.
The former Formula 1 driver said he "expected to continue racing with the fine people of Andretti Autosport in the coming years," adding that he was "disappointed that is not being fulfilled."
The team is yet to respond to Grosjean's statement, which he posted on Wednesday evening.
The statement read: “I enjoyed working with the IndyCar team at Andretti Autosport, and am proud of the successes we shared through two seasons. I am thankful for the many friendships developed at the highest level of American open-wheel racing.
“I had expected to continue racing with the fine people of Andretti Autosport in the coming years. I am disappointed that is not being fulfilled, and wish Andretti team members well. I am pursuing other options to continue my IndyCar career in pursuit of excellence.
“I have commenced an arbitration proceeding in Indiana against Andretti Autosport, seeking to protect my rights. I am represented by John Maley and Mark Owens of Barnes & Thornburg, LLP.”
Grosjean, who made 179 starts in F1, joined Andretti following a maiden campaign in North America’s premier open-wheel championship with Dale Coyne Racing with Rick Ware Racing in 2021, where he scored two runner-up results with one additional podium and a pole while contested 13 of 16 races.
In 34 races across the past two seasons with Andretti, Grosjean netted three runner-up finishes, five top fives and two poles. He finished 13th in the championship standings both years.
The mixed results left uncertainty regarding Grosjean’s future status with the Michael Andretti-led organisation. At the beginning of last month, he confirmed his exit from the team to NBC Sports.
During that time, he admitted talks with other teams, and Autosport confirmed one of those he shared discussions with was team owner Dale Coyne.
Andretti Global currently have three drivers confirmed for the 2024 season in the IndyCar Series, with 2022 Indianapolis 500 winner Marcus Ericsson coming over from Chip Ganassi Racing alongside Colton Herta and Kyle Kirkwood.