Leeds want to add to their growing American contingent by snapping up McKennie and made their move after speaking with boss Jesse Marsch.
They are trying to sign McKennie from Juventus on loan with an option to buy, but have not yet managed to convince the Bianconeri on the structure of the deal.
And while there is no deal done, Leeds are at risk of seeing their swoop for the midfielder hijacked.
Nottingham Forest are now looking at potentially hijacking the deal for McKennie as they bid to make signings before the window closes.
The Tricky Trees are admirers of the midfielder and are weighing up whether to try to take him to the City Ground.
They could look to take advantage of Leeds having failed to agree a deal for McKennie so far and work to tempt him to join them instead.
It is also suggested that interest in McKennie is growing ahead of the transfer window closing, indicating more clubs may well yet join the hunt.
