INDIANAPOLIS (AP) -- James Hinchcliffe's tough IndyCar start is getting more clouded.
E.J. Viso replaced the injured Canadian on Sunday in the opening practice for the Indianapolis 500 and it's still unclear when the popular Hinchcliffe will turn his first laps on the famed 2.5-mile oval.
Hinchcliffe was injured Saturday in the inaugural Grand Prix of Indianapolis when debris from Justin Wilson's car flew into the cockpit, striking Hinchcliffe in the head. He was taken away from the track on a stretcher, transported to a hospital and diagnosed with a concussion. He was hoping to be re-examined Sunday, but that never happened and now he's out until at least Tuesday.
"We'll have a better feeling then," team owner Michael Andretti said. "They just said rest and they don't want to see him again until Tuesday."
Later, the team issued a statement saying that exam date has been scheduled.
Traditionally, IndyCar drivers with concussions have missed a minimum of seven days off before being cleared to race. But series officials issued a statement Sunday night, saying concussions are handled on a case-by-case basis and that drivers with head injuries must pass an ImPACT test before they're cleared to compete by series medical director Dr. Michael Olinger.
If Olinger adheres to the strict timeline, though, Hinchcliffe would miss the only full week of Indy practice and might not be back in the No. 27 Honda until next weekend when the only two qualifying sessions will be held.
Andretti brought in Viso, who hadn't even been in an IndyCar this season until completing 28 laps Sunday.
Even Viso isn't sure what to expect next. He finished sixth on the speed charts with a fast lap of 222.105 mph. Twenty-four cars made it onto the track. Australia's Will Power, who drives for Roger Penske, was the fastest of the 24 cars at 223.057 mph.
Viso said he is prepared to do whatever Andretti's team needs -- even if that means replacing Hinchcliffe for qualifying or in the May 25 race.
"It's too early to know. It just happened yesterday and nobody knows how he's going to recover. It 100 percent comes down to his recovery," the Venezuelan said. "First of all, I just wish James a quick recovery. If he takes a little bit longer and I'm able to drive and do the job for him I'm, of course, not disappointed with that. But for me, the most important thing is to understand that he's recovering fast."
He has made six straight starts in the 500, including a career best fourth last year. Viso finished 18th in 2013, matching his best career finish at Indy.
The team said Hinchcliffe did make a brief appearance at the track to meet with his crew and have lunch with his family. He also spoke briefly with Viso but did not take questions from reporters.
For the popular Canadian driver, it's already been a challenging season. He started second at Long Beach and Barber but has not finished higher than seventh in any of this season's four races. He qualified 11th for Saturday's race, then wound up 20th after leaving with the head injury.
In Hinchcliffe's three previous IndyCar seasons, he's had 14 top-five finishes in 50 starts and won three races -- with all three coming last season.
What everyone wants to know now is whether he'll get a chance at a third straight top-nine qualifying run at Indianapolis?
"He seems in good shape and he's going to recover fast," Viso said.
Andretti Autosport has five cars, including NASCAR's Kurt Busch, trying to qualify for the May 25 race.
Ryan Hunter-Reay had the fastest car of the bunch, turning a lap of 222.134 on Sunday.
Busch, who is trying to become the fourth driver to race 1,100 miles in one day, at Indianapolis and Charlotte, was 12th at 220.352.
Copyright © The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.