insidethegames understands that the 75-year-old suffered setbacks after a third spinal column operation earlier this summer.

He is now keen to focus on his recovery and will thus play no further part in the PASO contest.

This currently leaves four contenders ahead of an election expected to take place in February.

Two of these are from the Caribbean region, St Vincent and the Grenadines' Keith Joseph and St Lucia's Richard Peterkin.

Neven Ilic and Carlos Nuzman, the respective Presidents of the Chilean and Brazilian Olympic Committees, are also expected to stand.

Puello, whose 76th birthday is tomorrow, is now expected to endorse both Joseph and Peterkin.

The trio had previously vowed to work together and eventually unite behind one candidate in order to best boost the Caribbean cause.

He plans to talk with his advisers over the weekend before making a formal announcement early next week.

Peterkin has already expressed his concern as to Puello's health before adding that he hopes the Dominican will remain involved in the future governance of PASO in some capacity.

"I believe that Dr Puello was a worthy adversary and the contest for the PASO Presidency is the poorer for his withdrawal," added Joseph.

"He has worked in the Olympic Movement at different levels for a very long time and his wealth of experience remains a treasure trove for all of us interested in rising to the leadership of the Movement in the Americas.

"I do believe that there is a place for Dr Puello, once available, in forging a new PASO."

The election is set to be controversially delayed until February despite a PASO constitutions requirement that it be held in the year following a Pan American Games, which means it should take place in 2016.

Uruguay's Julio Maglione is currently leading the body on an interim basis, but there has been no permanent President since the death of Mexico's Mario Vázquez Raña in February 2015.

Vázquez Raña had held the position since 1975.

An Extraordinary General Assembly is due to take place in Doha during meetings of the Association of National Olympic Committees on November 17, but this will take place solely to give final approval to the organisation's new constitution. 

A specific date or location has not been given for the meeting in February.

A three month electoral process cannot begin until these Statutes have been ratified.

Of the four remaining contenders, Nuzman's remains the most volatile candidacy.

The Brazilian, the President of Rio 2016, had vowed to wait until after the conclusion of the Olympics and Paralympics to decide.

He has not yet made an announcement either way.