INDIANAPOLIS – It was only a short practice session before this afternoon’s Pole Day qualifying at the 100th Running of the Indianapolis 500 presented by PennGrade Motor Oil, but it provided plenty of intrigue.

Each of the three practice groups received 30 minutes on track. The fastest overall was rookie Alexander Rossi in the No. 98 NAPA Auto Parts/Curb Honda with a lap of 230.064 mph that came without the aid of a tow.

Among those who will compete in the Fast Nine Shootout to decide the pole winner, Josef Newgarden was quick at 229.906 mph in the No. 21 Preferred Freezer Chevrolet. But that’s where the intrigue begins.

James Hinchcliffe, the fastest of Saturday’s first-day qualifiers, never took the track for the session. Likewise, his Schmidt Peterson Motorsports teammate Mikhail Aleshin kept his car in the team’s Gasoline Alley garage, as did Team Penske’s Simon Pagenaud.

Adding to the drama, 2015 Indy 500 pole sitter and Verizon IndyCar Series champion Scott Dixon will see his car undergo a rapid engine change after fluids were spotted leaking from his No. 9 Target Chip Ganassi Racing Chevrolet in practice.

Dixon is 21st in the qualifying line for the session that begins at 2:45 p.m. ET to determine race starting positions 10-33. Each driver makes one four-lap qualifying attempt at its designated position in the order.

Group 1 qualifying for positions 10-33 runs from 2:45-4:45 p.m. ET. The Fast Nine Shootout to set the front three rows of the grid, including the Verizon P1 Award for the pole position, runs from 5-5:45 p.m. Coverage is on ESPN3 (2:30-4 p.m.) and ABC (4-6 p.m.), plus the Advance Auto Parts INDYCAR Radio Network. Live timing and scoring is available at RaceControl.IndyCar.com.