However, those titles have since fragmented following Crawford's retirement.
In December, the IBF looked to install a new champion by ordering No. 1-ranked Iglesias against No.3-rated Canelo, who sits one spot below an empty No.2 position.
As Canelo has passed up on the opportunity, the IBF are due to move back down their rankings to find the next available contender to take on Iglesias.
At the time of writing, Jaime Munguia is ranked No.4 after being cleared of all wrongdoing relating to a failed drugs test following his win over Bruno Surace in May.
Britain's Callum Simpson currently occupies the No.5 slot, although he is very likely to be removed in the next update after being knocked out by Troy Williamson on December 20.
Canelo's decision to reject the Igelias fight comes as little surprise to those in the know.
The Mexican's trainer and manager, Eddy Reynoso, confirmed last month that Canelo would forgo his usual Cinco De Mayo weekend date and elect instead to return to the ring in September.
Canelo underwent arthroscopic surgery on his left elbow in October, which requires 12 to 15 weeks to recover from.
He was scheduled to return in February as part of his four-fight deal with Riyadh Season, but his operation delayed the expected return date to May.
That has since been pushed back a further four months, with Canelo aiming to box on Mexican Independence weekend.
Against whom remains a mystery.
A rematch with Crawford is out of the question, not only because 'Bud' has now hung up his gloves, but also because of the lopsided nature of the defeat.
Source: talksport.com
