With Foreign Secretary S. Jaishankar, who is widely known to have the ear of Prime Minister Narendra Modi, set to retire on January 28, the grapevine in South Block and foreign policy circles is abuzz about whether he is going to get another extension.

Jaishankar was appointed Foreign Secretary on January 29, 2015, a couple of days before his retirement, replacing Sujatha Singh who resigned in protest seven months before her date of superannuation. 

Jaishankar is known for his proximity to both Modi and National Security Advisor Ajit Doval and his experience of having served as Ambassador in China and the US stands him in good stead. 

With Donald Trump taking over as the US President, Jaishankar's experience will be invaluable in dealing with the new administration. He has already been to Washington and met key members of the Trump transition team prior to the US presidential inauguration on January 20.

The other immediate contenders by seniority for the position would have been Secretary (West) Sujatha Mehta, Secretary (Economic Relations) Amar Sinha and Indian Ambassador to the US Navtej Sarna, who was shifted from London to Washington after only seven months, Ambassador to Italy Anil Wadhwa and Ambassador to Nepal Ranjit Rae.

But with all of them set to retire at various times this year, it is unlikely for them to be considered and then be given an extension. 

Ambassador to China Vijay Gokhale was at one time talked about to replace Jaishankar. If Jaishankar is given a one-year extension, then Gokhale can even make it for one year. However, a two-year extension will nix Gokhale's chances. 

"The Foreign Secretary's post is given to someone who has the best diplomatic accomplishments to his or her credit. If this criterion is followed, then Jaishankar stands head and shoulders above the others," said a former colleague of Jaishankar who retired as an ambassador last year. 

Jaishankar, a known workaholic who, according to insiders, often sleeps nights on his office couch, has been an astute articulator of the Modi foreign policy vision. 

If he is replaced, it has to be by someone who Modi -- and External Affairs Minister Sushma Swaraj and Doval -- know well and would be ideologically comfortable working with him or her, particularly in such challenging times for international relations. And that person may be hard to find.