Dragon Racing team owner Jay Penske dropped a $4.6 million lawsuit against Lotus last month in order to be released from a contract to make a deal to use Chevrolet engines. Chevrolet, though, is providing the team with only one engine for the rest of the season.
"I'd love to have two Chevrolets on track every weekend," Penske said. "But I remain extremely grateful to Chevy for stepping in at the last minute and providing us not only the two engines for Indy, but also committing to provide us full support for a single entry for the rest of the season which they were under no obligation to do."
Bourdais was in each of the first five races this year with one top-10 finish. His sixth start on Sunday in Detroit will be his last for a month because the next three events - in Texas, Milwaukee, and Iowa - are on oval tracks.
"We know it's time to show what we're capable of," he said. "The sooner the better."
Among points leaders, Bourdais is 21st and Legge, who also raced in IndyCar's first five events, is 24th out of 33 drivers.
Dragon Racing became the third team to ditch the Lotus engines.