Already strapped for cash thanks to the funky financing of the new Tappan Zee Bridge, the state Thruway Authority now faces an unexpectedly large bill for repairs on the three-mile stretch of I-90 — thanks to Gov. Andrew Cuomo’s failed effort to use the project to blackmail the sovereign Seneca Nation.

The highway — riddled with potholes and marked with “Rough Road” signs — turns out to be “in far worse condition than we had anticipated,” Thruway exec Matt Driscoll wrote the tribe this week.

Because the state didn’t repair the road’s asphalt surface in time, the concrete base suffered major damage. The job’s now too big to handle before winter; it will put the work up for contracting come spring.

Cuomo pretended the delay was the tribe’s fault, claiming it was refusing to allow access to the stretch of highway that runs through its lands because of an ongoing dispute about payments to the state related to its casinos.

Except the Senecas had no reason to stall — they don’t think they owe the money that the gov wants, and he can’t make them pay. He was clearly the one taking I-90 hostage.

He failed — but it’s the public that’ll have to pay the price when the Thruway Authority has to raise the extra cash.

It’s only a fraction of the authority’s burden thanks to the Mario M. Cuomo (nee Tappan Zee) Bridge, but it’s another guarantee that tolls will soon soar.