The Andretti Autosport driver was released from Lehigh Valley Hospital - Cedar Crest in Allentown on Saturday evening, having been taken there by road for checks after a heavy impact with the wall during qualifying.
But an IndyCar statement said Hunter-Reay, who suffered hip and knee injuries, was not yet cleared to drive and would be re-evaluated on Sunday morning.
"I hit my hip pretty bad as well as my knee, so the doctors thought it would be best to go in for further evaluation.
Hunter-Reay's accident was one of three big impacts at Pocono on Saturday, with Ed Carpenter crashing in practice and Helio Castroneves doing so shortly before Hunter-Reay in qualifying.
Carpenter, who missed qualifying, and Castroneves were both able to run in Saturday evening's final practice session in their repaired cars.
- Ryan Hunter-Reay released from hospital after IndyCar Pocono qualifying crashUSA TODAY
- Indianapolis 500 champion Takuma Sato wins Pocono poleThe Mainichi
- Insider: Alexander Rossi plays key role in Takuma Sato's daring run to pole in ...Indianapolis Star
- ABC Supply 500 qualifying results: Takuma Sato on poleFanSided
- Medical update on Verizon IndyCar Series driver Hunter-ReayINDYCAR
- Andretti driver Takuma Sato will be on the Pocono poleAllentown Morning Call
- Indianapolis 500 champion Takuma Sato wins Pocono pole; Hunter Reay injured in ...WTHR
- Crashes mar day for several drivers at Pocono RacewayINDYCAR
- Dramatic run earns Sato pole position for ABC Supply 500INDYCAR
