The forward flew in from Spain yesterday ahead of his move, keeping fans updated via his social media channels.
Supporters even gathered at Elland Road to meet the former Real Madrid youngster, although there is one supporter who may not be so thrilled.
On Twitter at the end of last month a fan pledged to get an embarrassing tattoo if both the Saiz deal went through and Leeds bought stadium Elland Road.
If Leeds sign Saiz and buy Elland Road back I'll get Cellino's son eating a Burger King tattooed on my arse.— Daniel Fieldhouse (@Fieldhouse7) June 23, 2017
Leeds bought back Elland Road last month in a momentous move, having leased the stadium for the past 13 years.
Under any previous owner, the pledge likely would have been safe.
Leeds United fans
New supremo Andrea Radrizzani is very different. The Italian is a man of action, who has led a wave of impressive acts since taking over.
He has renewed contracts of key players, overseen several signings, and the Elland Road deal was the icing on top.
He would be almost worth getting a tattoo of. Massimo Cellino's former director son on the other hand, perhaps not.