CHEVROLET DETROIT GRAND PRIX: Combined practice results I Qualifying groups

Following three practice sessions on Friday, Rossi sat atop the timesheet with a best lap of 1 minute, 15.1367 seconds (112.595 mph) around the Raceway at Belle Isle's 2.35-mile, 14-turn temporary street circuit. The Andretti Autosport driver and 2016 Indianapolis 500 winner was 0.5274 of a second quicker than Josef Newgarden but wasn't sure it was an accurate reflection of the results.

"Considering most of the guys didn't get a run on reds (Firestone alternate tires), I'm not sure how relevant our session times were," said Rossi, driver of the No. 27 NAPA AUTO PARTS Honda who finished a narrow second to Simon Pagenaud in Sunday's 103rd Indianapolis 500 presented by Gainbridge. "Overall, I think the team has carried on well from last year. We had a good car last year; all four cars were strong. To be able to pick up where we left off is a strength."

Newgarden was second for the day with a lap of 1:15.6641 (111.810 mph) in the No. 2 Hitachi Team Penske Chevrolet. Like Rossi, Newgarden was unclear if his effort was worthy of the standing.

"I think we had a decent start today, not 100 percent sure where we stack up," he said. "I think we're a little bit further back than where we were on that final red-tire run. Some of the Andretti boys look really good, some of the Ganassi guys look really good. We'll see."

Following Rossi and Newgarden on the speed chart were the four most recent winners of Detroit races. Scott Dixon, winner of Race 1 last year, was third in the No. 9 PNC Bank Chip Ganassi Racing Honda (1:15.7824, 111.635 mph); Will Power, winner of Race 2 in 2016, was fourth in the No. 12 Verizon Team Penske Chevrolet (1:15.8713, 111.505 mph); Ryan Hunter-Reay, winner of Race 2 in 2018, was fifth in the No. 28 DHL Honda (1:15.9896, 111.331 mph); and Graham Rahal, who swept to victory in both 2017 races, was sixth in the No. 30 Fifth Third/United Rentals Honda (1:16.0757, 111.205 mph).

Simon Pagenaud - winner of the two most recent NTT IndyCar Series races, the INDYCAR Grand Prix and 103rd Indianapolis 500 presented by Gainbridge - placed 10th overall in Friday practice with a lap of 1:16.2923 (110.889 mph). Pagenaud did cause a red-flag stoppage of practice when his car brushed the wall exiting Turn 12, causing light left-side damage to the No. 22 DXC Technology Team Penske Chevrolet.

Pagenaud leads Newgarden by one point atop the standings heading into the weekend. Rossi is third in the championship, 22 points behind Pagenaud.

With practice now complete, the focus shifts to a qualifying session and 70-lap race each of the next two days. Qualifying differs from the normal knockout round system used at other NTT IndyCar Series road and street courses. Instead, the 22-car field is split into two groups, with each receiving 12 minutes of track time. The fastest overall driver wins the NTT P1 Award pole position for the race, with the fastest driver in the other group starting second. Each group's fast driver earns a championship point.

Race 1 qualifying begins at 10:45 a.m. ET Saturday. It streams live on INDYCAR Pass on NBC Sports Gold, with a delayed telecast at noon on NBCSN. Coverage of Saturday's race begins at 3 p.m. on NBC and the Advance Auto Parts INDYCAR Radio Network.

Qualifying on Sunday airs live at 10:30 a.m. on NBCSN, with race coverage commencing at 3 p.m. on NBC and the Advance Auto Parts INDYCAR Radio Network. 

On the 30th anniversary of the first Indy car race in Detroit, Sunday's race will mark the 30th Indy car race to take place in the Motor City. Races were held on a downtown street circuit from 1989-91 before moving to the Belle Isle circuit, with events held from 1992-2001, 2007-08 and annually since 2012. The Chevrolet Detroit Grand Prix has conducted a doubleheader weekend each year since 2013.