The last time these two sides came together was in February, a Premier League contest settled by Rooney with a stunning bicycle kick at Old Trafford.
Now the Manchester rivals once more go head to head, this time in the Cup, and Richards has said City will try everything in the book to make sure the England striker has a quiet game.
Richards said: "We know we'll have to keep our eye on Wayne. We won't let him do that again.
"If he tries one of those overhead kicks again then maybe I'll have to give him a little elbow this time.
"Because it's United, it does make the tie a little bit special. But I think it would have been even more special had it been the final.
"We would have preferred that but at least we know if we beat United, there's a really good chance we could win it."