McCormack agreed a deal away from Elland Road in the early hours of this morning, with a fee of around £11 million believed to have been exchanged between Fulham and Leeds for the acquisition of his services.
Whilst the fee is astronomical for a deal between two Championship club, the immense goalscoring ability of McCormack may be the difference between the Cottagers achieving an immediate return to the Premier League, rather than having to linger in the second division for longer than they intend to.
The Scottish international netted 28 goals in 46 league games last season, and, although Leeds only ended the season in 15th place, they can be grateful that McCormack's goals were enough to pull them out of a possible relegation battle. He scored 47% of the Whites goals last season, single-handedly winning games by himself.
Leeds will be thankful for the fee they have received for their former star striker, although, whilst they can now start to rebuild a squad capable of challenging for promotion, they have also got to replace the 28-goal striker they have let go.
Whilst the pre-season at Elland Road will be concerned with filling the void left by McCormack, Leeds' Championship rivals Watford will be delighted with the completion of the deal - knowing that it reduces the chance of Troy Deeney moving away from Vicarage Road.
Deeney also hit the 20-goal mark last season, netting 24 times in 44 games - just four goals fewer than £11 million man McCormack.
A move away from the Hornets has been rumoured, with a host of lower table Premier League clubs interested in securing the powerful strikers services - including newly promoted Burnley, who have had a formal bid rejected by Watford officials.
With the departure of McCormack, Watford management now have a benchmarked value for their star striker - who has scored eight more goals that McCormack is the past two seasons. If McCormack - who will be 28 when the season starts - can be worth £11 million, Watford will be holding out for a fee of roughly the same value - or potentially even more - for Deeney - who is two years younger that his former Yorkshire-based rival.
The £11 million fee was also accepted with McCormack lobbying for a move away from Elland Road, meaning the club had to accept a cut price fee for the player. With Deeney apparently happy at Vicarage Road - where the Hornets faithful adore him - there is no chance of him forcing a move away - unless a top Premier League club come in for him.
Whilst Leeds will be delighted with the large fee they received for their star, there is no hiding the fact that replacing McCormack will be an incredibly hard job. Meanwhile, it appears as if Deeney will be staying at Watford. Lower table Premier League clubs will be unwilling to splash out upwards of £10 million for a forward untested in the top flight, and the player himself would be unwilling to make a sideways move to another Championship clubs.
Keeping hold of Deeney will be one of the best pieces of transfer business the Hornets could complete this transfer window, and, with the reinforcements already brought in, it promises to be a exciting season for the Hertfordshire club.