He came off the bench in his first match for England against the Boks in Johannesburg then started the second test, only to pick up an illness that resulted in him being admitted to hospital and shedding considerable weight.
Even now, Shields has not yet fully recovered.
Shields also picked up a few stitches above his left eyebrow after a training-ground collision with Ambrose Curtis, while the culprit of his illness is suspected to be a rogue chicken sandwich that he consumed with his parents.
"It looked pretty good to me – I made sure I checked it – but then it went from there," Shields said.
"It was pretty bad. It was the worst I have been sick in my life. Usually it lasts for a couple of days but this was about 10 days by the time I got back to New Zealand, started putting some weight back on and started to feel normal again.
"I lost about seven or eight kilos during the time I was ill – mainly in fluid. Although I didn't think I was too bad, they took me to hospital and put me on a drip once they realised how much I'd lost. It took a wee while to bounce back. I'm still sort of bouncing back from that now I guess, putting on all that weight, but I'm feeling pretty good."
England's first autumn test is against South Africa on November 3 and a week later they play the All Blacks in a much-awaited clash at Twickenham.
The All Blacks round off their end-of-year tour against Ireland and Italy in successive weeks.
