Ferguson confirmed the Old Trafford pitch will be ripped up at the end of the season.
He said: "It has never recovered from the deluge we suffered over Christmas. Before that it was fine. It has been down for nine years now and it needs to be replaced.
"We have to hope for better weather and a bit more sun. We've got artificial lights on it all the time which really helps but the more light we get the better it is for the pitch.
"We're changing the whole pitch in the summer but at the moment it's not good. It's definitely a bit worn out. The groundsmen work their socks off and Tony Sinclair is as concerned as anyone.
"We've declined to replace the turf because we believe Tony will get it right.
"But there's no question it's still recovering from those two games over Christmas. That killed us and it's never been the same since."