Tottenham are being linked with a move for Manchester United midfielder Michael Carrick.
The News of the World says Carrick is uncertain of his position, with old club Spurs retaining an interest in a deal involving Croatia star Luka Modric heading for Old Trafford.
Ferguson believes England international Carrick, who has scored just once for United this season, should have more say in the centre of midfield.
Carrick's role is just one of several vulnerable positions Ferguson has pinpointed in the team.