The premature split between Kostecki and Tickford, just one year into a multi-year deal, has been on the cards since late last year.
Kostecki then took to social media to make his own statement regarding the split, indicating that he would assess his options moving forward.
"I have [parted] ways with Tickford Racing before the 2023 season, that means I’ve missed out on a full-time seat in the Supercars," he wrote.
"While looking forward to the new era of Supercars it wasn’t meant to be for now.
It’s not all sunshine and rainbows [in real life] but I just need to work out what’s best for me and what’s next.
"I’ll see you all soon. Thanks to the crew Tickford Racing, the whole team at Tradie Brand, Ford Motor Company and the support from everyone. It has been nice."
Kostecki's exit paves the way for Super2 champion Declan Fraser to make a somewhat unexpected debut in the main game with Tickford this year.
Fraser had looked to be set for a year on the sidelines after the vacant seat at Matt Stone Racing – at the time the only solid vacancy on the grid – went to Super2 teammate Cameron Hill.
The Fraser/Tickford deal could be made official as soon as this week.
