NFL running back Isaiah Pead seems to be in good spirits -- or as good of spirits as he could be in -- while recovering from a bad car crash ... smiling in multiple pics from the hospital.

Pead was badly hurt when he wrecked his car in Ohio around 2 AM on Saturday -- and his injuries are so bad, his family says his football career is over.

But despite the bad news, the 26-year-old mustered up a smile when he was visited by an old friend the other day -- University of Cincinnati Asst. Athletic Director Bob Mangine ... who specializes in sports medicine.

Mangine brought over Pead's old college football jersey -- which elicited a smile from the RB.

Pead also posed for a pic in front of the hospital -- sporting a smile while seated in his wheelchair.

We've reached out to Pead to find out how he's doing. We'll let you know if we hear back.