Briscoe joined Prema for its inaugural IndyCar campaign as the sporting director where he guided drivers Robert Shwartzman and Callum Ilott.

At Rahal Letterman Lanigan Racing, he will act in a similar role as a driver coach for Graham Rahal, Louis Foster and Mick Schumacher.

Briscoe is one of two recent appointments to RLL, the other being Mike Pawlowski, who will engineer Schumacher in his maiden IndyCar campaign.

“Rahal Letterman Lanigan Racing has the foundation, infrastructure and commitment,” said RLL president Jay Frye.

“We have made multiple, impactful strategic additions this off season, the latest being Ryan and Mike as we position our IndyCar program to compete at a high level on a weekly basis.”

The Briscoe departure is one of several blows for Prema amid continued speculation about its future.

Earlier this month, Prema co-founder Angelo Rosin and his son Rene Rosin, who is the team principal, split with the team.

Neither Shwartzman nor Ilott were named for this week’s IndyCar content day, where every full-time driver is expected to attend.

Rumours persist that the team is seeking new ownership, and missing the season opener is possible.

Financial issues have long hung over Prema. Even as Shwartzman famously took pole position at the Indianapolis 500, there was speculation that the team was in financial strife.

Whether the team competes in 2026 remains unclear. In any case, the season will begin on the streets of St Petersburg in a month on February 27-March 2.