Then Daniel Carter was out of the squad on the day before the All Blacks' final pool match, and back-up Colin Slade went down in the quarter-final against Argentina.
"I joked with someone that Beaver would be getting the call up, because at that time everyone thought Piri Weepu would slot into No10," Mr Lawrenson said.
"I texted him and said, 'mate, are you in the squad?' And he said, 'yeah mate, I am so pumped up I can't wait'."
Less than halfway through the nail-biting final against France on Sunday night, it became no laughing matter - Aaron Cruden was hurt and it was Donald's time to shine.
He kicked the winning penalty and was yesterday hoisted through cheering Auckland crowds in the All Blacks' victory parade.
The match had been a blur, he said, hard to separate from any other game of footy.
"It was just getting the job done, and we're probably not appreciating just how big the job we've done is," Donald said.
But he never doubted that he could rise to the occasion.
"I've played test rugby before and when I get excited about it I tend to play well."
It was not the game that stood out for him, but later sitting in the changing room knowing the team had done it and seeing masses of crowds celebrating, he said.
"It's a pretty special time - the game goes very quickly, it's all a blur, but this sort of stuff, seeing this many people, you're not going to forget that in a hurry."
A poor outing at a Bledisloe Cup test about a year ago resulted in Donald being relegated to the back of All Black selections, and he made the decision this year to leave New Zealand for English team Bath.
"It's quite weird [now], but at the time I was well out of the picture. Obviously now things are just all as it is. It's a bit irrelevant to think about it," he said.
"Life throws curveballs here and there and it's a rollercoaster ride, but it's the way it's happened."
Donald's mother, Sheryl, said she had known her son would prove his critics wrong when he was called off the bench.
Seeing him rescue the flagging All Blacks side was one of the proudest moments of her life, she said.
"It was amazing. It was great.
"I spoke to him soon after the match. There is definitely joy at the win."
Controversial Samoan player Eliota Sapolu tweeted after the game: "Donald haters, eat your words. Well done bro. Really happy for you."
Donald has said his nickname came from being an ugly child, having two big front teeth, and looking like a character from the television show Leave It To Beaver.
additional reporting APNZ
