The impact of the wreck tore out a large section of fencing that IndyCar said would take at least one hour to fix.
IndyCar released a statement after the race saying the 29-year-old suffered "orthopedic injuries" but declined to go into details.
The race was delayed almost two hours and only eight laps in the 500-mile race had been completed because of Wickens' crash and another accident right before green.
Power had one more shot to jump Rossi in the pits, but just before he dove in on lap 171, he went high while trying to pass the lapped auto of Max Chilton and lost valuable seconds, clearing the way for Rossi to win his first oval race since the 2016 Indy 500.
The Verizon IndyCar Series race was red flagged and did not restart for approximately two hours after the crash, which occurred at approximately 2:30 p.m. He was one those who was treated at the race track medical facility and released.More news: C$ gains as accelerating inflation raises rate hike prospects
Sunday's IndyCar race at Pocono Raceway got off to a scary start. Wickens vehicle smashed into the wall and climbed up into the catchfence. "I'm glad there is three races left in the championship, trying to get some good results and I'm looking forward to Gateway".
"We he had a run out of turn 1, Robert came up along the side of me, but I was in the draft of (Will) Power in front of me, so I started pulling ahead". Teammate and fellow Canadian James Hinchcliffe was also involved in the crash. Graham Rahal got into the back of Spencer Pigot before the race even got to green. Behind them, the accordion effect collected the second SPM Honda of James Hinchcliffe, Dale Coyne Racing's Pietro Fittipaldi and Rahal Letterman Lanigan's second vehicle of Takuma Sato, all fortunately without serious injury.
Despite leading five times for 69 laps, Wickens finished 18th in the race.
Scott Dixon leads the championship standings as he chases his fifth IndyCar championship.
After 14 races, Dixon has accumulated 530 points to 501 for Rossi. "I love it. It's in our blood", said Bell.More news: Crotty, Ioane to miss second Bledisloe Test
Everyone except the race victor, who was in firm control of the outcome.
"We came out in some traffic - it was really, really hard to get behind cars for some reason today", Rossi said. "I saw that Ryan was out of his auto".
"Yeah, I mean, it's Rob, it's anyone, doesn't matter who it is". Those ones hit a bit closer to home. We try our best to look after each other out there.
"That's the worst thing you can see. I hope to talk to him soon, like I said, give him my regards".More news: Kevin Spacey's New Movie Grosses Just $126 on Opening Day