Simon Pagenaud has topped the final practice session before Carb Day on Friday, clocking a best lap speed of 228.273 mph.
Pagenaud, who claimed pole position for the 103rd running of the Indianapolis 500 on Sunday, jumped to the top of the timesheets in the final moments of the session.
Josef Newgarden was second behind his Team Penske teammate, while James Hinchcliffe ended the session in third.
Hinchcliffe secured a starting place on the final row of the grid on Sunday, alongside Sage Karam and Kyle Kaiser.
Hinchcliffe's teammate Marcus Ericsson hit the wall at Turn 3 during the session, as he got caught up in traffic. The Swede had his contact towards the end of the two hours of green flag running but managed to get away without major damage.
Scott Dixon and Alexander Rossi were fourth and fifth respectively, with the latter exploring passing possibilities after his overtaking show twelve months ago.
Charlie Kimball was sixth, ahead of the other two Penske cars of Helio Castroneves and Will Power.
Felix Rosenqvist was ninth, while James Davison rounded out the top ten with a best lap speed of 227.393 mph.