Just two days into Indianapolis 500 practice, and Chevrolet is already facing some serious engine trouble. The manufacturer, which powers 18 of the 33 cars in this year's race, has had to replace three engines in the opening sessions at Indianapolis Motor Speedway—raising eyebrows and concerns among its drivers.

Tuesday's first practice saw Ed Carpenter Racing's Ed Carpenter and Team Penske's Scott McLaughlin both sidelined with engine issues. While a Chevrolet spokesperson noted the problems were "not the same issue," the pattern continued into Wednesday. That's when Carpenter's teammate, Alexander Rossi, also had his engine swapped out after practice, with the original unit sent back to GM's Detroit headquarters for analysis.

"I am concerned," Rossi admitted Thursday morning. "It's not only Ed and I, there's been two others as well. We don't have the full information as to are they the same failures? Is it something that's a batch thing?"

Despite the early setbacks, the mood isn't all doom and gloom. Rossi acknowledged Chevrolet's track record and commitment to resolving the issues quickly. "All that I know is that Chevy is just as focused on making sure that we can have a strong month. We know that, for the most part, we're the engine to beat, so hopefully the bad luck's out of the way."

With qualifying and race day still ahead, all eyes will be on how Chevrolet responds. For now, drivers and fans alike are hoping these early hiccups are just that—early. Because in the high-speed world of the Indy 500, reliability isn't just important; it's everything.