TORONTO — Jimmy Vasser's return to competition at Toronto was short-lived after a hard landing in one of Robby Gordon's trucks sent the former champion to the hospital for X-rays.

Vasser was scheduled to run both Saturday and Sunday in the Gordon-owned Speed Energy Stadium SUPER Trucks series, but only made it through two laps in Saturday morning's practice because of a rough landing.

Vasser said he did exactly the opposite of the instructions Gordon gave him before practice for the series in which trucks slide through the corners and jump ramps that make the trucks sail 50 feet through the air.

"Robby told me to lift off a bit before the ramp, and then power up the ramp," Vasser said. "Apparently I didn't lift enough, and I powered more than I should have. I looked out the window and I was over the fence line and it was pretty cool — until I landed and the whole truck hit the ground, and my back went crack, crack, crack."

IndyCar orthopedic specialist Dr. Terry Trammell sent the 1996 CART champion to a hospital for X-rays. Vasser said the X-rays looked fine at the hospital, but the pictures were sent back to the track for Trammell to give a second opinion.

"I can barely sit. It hurts," Vasser said. "We're still waiting for Trammell to take a look at the X-rays, so I wasn't cleared to drive. But I'm in no shape to drive."

Vasser, who co-owns Indianapolis 500 winner Tony Kanaan's car, was using a soft padded stool to sit on while he called Kanaan's race from the pit stand. He was replaced in the truck by former IndyCar driver Davey Hamilton.

Vasser said he would like to try Gordon's series again.

"It was my first time, I'll do it again, as soon as I can," Vasser said. "It was totally my error. I think it's a great series, the fans love it. They are very excited to watch the jumps and see the trucks slide around. I think Robby's got something with this series."