Rooney, on 202 United goals, is now chasing down Law's 237 goals record.
"One thing that Rooney's always shown since he's arrived at the club is that he's not only a goalscorer, but a person who tries, no matter what the scoreline is," Law told United Review.
"I wasn't surprised to see Wayne reach 200 goals for United. I said years ago that as long as he stayed fit he would become the highest scorer and I have no doubt he'll break the record."
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