James Hinchcliffe will make an immediate return to the cockpit after being given clearance to drive in Indianapolis 500 practice by IndyCar's medical team.
Hinchcliffe was sidelined with a concussion after being struck by debris during last weekend's IndyCar race on the IMS road course.
He had been made to wait after being assessed three times since, and was cleared after being re-evaluated and passing the post-concussion ImPACT test on Thursday morning.
EJ Viso has been shaking down Hinchcliffe's Andretti Autosport car down during the opening days of practice for the Indy 500 in the Canadian's absence, but Hinchcliffe will be back in the seat for the remainder of Thursday's running.
"It goes without saying, I'm thrilled to be back in the car," Hinchcliffe said. "It's been a long couple of days watching everyone practice, but obviously getting healthy was the number one goal.
"The car looks fast and I can't wait to get out there and get up to speed."