Paul Walker's death came at a terrible time for his Fast & Furious franchise co-star Dwayne Johnson, because the hulking action man was nursing a painful hernia when he got the awful news of the tragic actor's car crash.

Johnson was preparing for surgery on his groin last November (13) after telling his Hercules director Brett Ratner he'd have to hold up the shoot when he got the bad news.

The Pain & Gain star tells The Hollywood Reporter, "I came in for a check-up and pulled my pants down, and the doctor goes, 'Oh! That's a hernia...' Your abdominal wall gets weak and your organs push through. The doctor said, 'You need to lie down', and slowly starts to push my intestines back in my stomach. He said, 'I would really recommend surgery'."

That news came just two weeks before he and Ratner were set to start filming the historic blockbuster in Hungary.

Ratner tells the publication, "You think automatically because he's (Johnson) a bodybuilder, he can do that stuff, but he had to get up at two or three in the morning, work out, eat 10 times a day. He had to drink tremendous fluids to keep hydrated. I was always worried about burning him out because it's hard to maintain that level of energy. The crazy part is, three weeks before we started shooting, he whips his groin muscle and gets a hernia."

Johnson returned to his adopted Florida to rest up, and days later he heard the shocking news that his pal Walker had died in a fiery car crash in California.

He recalls, "I was driving with (girlfriend) Lauren when she immediately turned very quiet and was looking at me, studying, wondering if I knew. I pulled over and looked at my messages and had a moment where I just caught my breath.

"We said a prayer right then to give his daughter strength... Then, once we got home, we started bawling."