Series officials said the popular Canadian has made "substantial" improvement and is expected to make a full recovery without additional surgery. Dr. Timothy Pohlman, the surgeon who operated on Hinchcliffe, said the medical staff is pleased.
"His condition continues to improve," Pohlman said in a statement released by IndyCar. "Our expectation, in consultation with the IndyCar medical staff, is that a normal recovery is to be expected."
Hinchcliffe was injured Monday when he hit the wall in the third turn at Indianapolis, a crash caused by a broken suspension. A metal part pierced Hinchcliffe's left leg, causing significant blood loss.
He has been ruled out indefinitely, and Schmidt Peterson Motorsports has not yet announced a replacement driver for Sunday's Indianapolis 500.
The team is expected to introduce a new driver Thursday morning.
"Not fully, but we're trying," Sam Schmidt told The Associated Press when asked if he'd found a replacement. "Nothing is signed at this point."
Since Tuesday, the speculation has increasingly turned to Ryan Briscoe, the 2012 Indy 500 pole winner. Briscoe has made nine Indy 500 starts, three from the front row, and finished as high as fifth in 2007 and again in 2012.
Of his eight Indy 500 starts, five were for Team Penske and three were for Chip Ganassi Racing.
The 33-year-old Australian has competed in a couple of sports car races this season. With Hinchcliffe out indefinitely, Schmidt is looking for a driver who can stay in the car for a while.
"Certainly, he (Briscoe) makes a lot of sense from an Indy 500 record," Schmidt said. "We don't know how long Hinch is going to be out and we'd certainly like to keep some continuity. So it's a big of a juggling act right now."
Schmidt said Tuesday that there still is a possibility Hinchcliffe could return later this season.