Signed from Milwall exactly eight years ago today for a mere £1.5million, Cahill went on to amass an impressive tally of 56 league goals.
The 32-year old had not enjoyed the most prolific of seasons in the previous campaign, but was still recognised for his hard work and determination.
The Australian has always expressed a desire to end his career back in his homeland so the deal to take him to America will come as a surprise to many.
Elsewhere, Everton are believed to have completed a deal to bring Steven Pienaar back to the club on a permanent basis.