United's clean-sheet in last Saturday's 1-0 win at Everton heralded a return to the defensive solidity demanded by Ferguson, who admitted his side must overcome their perceived vulnerability at the back if they are to enjoy a successful campaign.
"Statistics have been bandied about in the last few weeks," said Ferguson. "But there has to be a balance in these matters. Nobody likes losing goals and we've lost a few this season.
"Secondly, in the second-half they were playing to their favourite end and it was very difficult to handle. They kept pumping that ball into the box and to withstand that you've done well not to lose a goal.
"The balance has got to be right [between defence and attack]. We don't like losing goals but we have to make sure the attacking part of our game is always threatening."