The duo have started upfront together in the last four games, scoring seven goals between them.
Ferguson believes that the partnership could become as valuable to the Red Devils as the one struck up between Dwight Yorke and Andy Cole, which helped secure the treble in 1999.
"I think last week [against Everton] we saw something really special," said Ferguson. "There were a lot of reference to the Yorke and Cole thing and there were similarities.
"Wayne is 26, Danny is 21 and you would think that for the next few years they can only get better. With Danny being fit again and playing consistently with Wayne it has developed."
Welbeck has notched nine goals this season, while Rooney is second in the Premier League scoring charts with 26 goals.