"I will not be attempting to bet anything with Cristiano this season unless it is 50 goals," he laughed. "Somehow I don't think he would accept that."
A more productive gamble might be on Ronaldo getting a much-prized United hat-trick.
While he has now scored twice on 10 occasions, the former Sporting Lisbon player is yet to hit a three-timer and could not manage it against Blackburn on Sunday despite the light-hearted promptings of Rio Ferdinand.
"In the second half I told Cristiano, he either had to score a hat-trick or get an assist to make it a really good game," Ferdinand said.
"He has been fantastic in the last few games and is determined to become a top player for many years.
"He works hard in training and you see the results out on the pitch. Long may that continue."