Mahendra Singh Dhoni’s future in cricket has frequently been under scrutiny in the past couple of years, even more so after he gave up the captaincy in limited-overs cricket last season.

For almost a decade—in which he was captain for more than eight years—Dhoni tasted unstinted accolades from fans and critics alike. His own prowess and the success of the team gave him a cult status that appeared to be invincible.

That is no longer true. To some extent, this was inevitable. Unless a captain is hopeless as player and leader, his pre-eminent position gives him not just power but also deep protection.

Surrendering (or losing) the job can change the equation dramatically. Immunity decreases and there is a corresponding rise in vulnerability. This becomes even more pronounced when a player is in his mid-30s, as Dhoni is now.

Does he still have it in him to play this level? Is this the right time for him to quit? Would the team be better served by a younger player? The questions have become frequent and more pointed.

These are impossible to answer with any degree of certainty. When is the right time to retire remains the most vexing decision for a sportsperson. No established formula or fixed age can be applied.

A fair number of players have stretched their careers into their 40s, some even into their 50s. There are stalwarts in other sports too with long and illustrious careers, but overall, the slower pace of the game helped cricketers play longer.

In the modern era, cricket is played virtually non-stop, has three formats, and has become far more athletic and demanding of better physical ability and psychological well being.

While modern sports science and psychology have been of enormous help to players, there is a threshold beyond which it’s impossible to extend careers. But this varies from player to player, which makes every theory fascinating, but also inconclusive.

Age is not necessarily a handicap. For instance, Rohan Kanhai played a pivotal role in West Indies winning the 1975 World Cup, though he was 40 at the time. Imran Khan was 39 when he led Pakistan to victory in the 1992 World Cup. Sachin Tendulkar was almost 38, and the highest scorer in the 2011 World Cup which India won.

But there are contra indications too. In the 1996 World Cup, Javed Miandad, then pushing 39, looked thoroughly spent and incapable of the magic which had helped him pull off some spectacular victories for his side in the past.

The imperatives for a player of any age—but more so one in the evening of his career—are physical fitness, mental toughness to compete and passion for the game. Without these, survival at the highest level would be impossible.

How does Dhoni fare on these parameters? Rather than conjecture, I would go by what team captain Virat Kohli has to say. “He’s concentrating on his fitness and contributing to the team in every way possible, tactically and with the bat."

Given his overt desire to succeed, I would like to believe that Kohli is not merely being deferential towards his former captain. Rather, he is convinced Dhoni has something substantial to offer.

There has been too much focus on Dhoni’s batting, especially the lack of big shots early on in the innings or the inability to finish a match in rousing fashion. But this is a one-dimensional view of his prowess, largely because of earlier achievements.

With advancing years, there will obviously be some diminishment in the sheer power of Dhoni’s batting. But that is something younger players should be able to compensate for. That’s how life and sport progress.

From a team perspective, the important consideration should be what Dhoni still has to offer even if he wins matches off his own bat less frequently. His wicket-keeping, while unorthodox, still remains fantastic. More than anything else, it is his rich experience—as player and past captain—and calming influence on a bunch of mercurial teammates that is still invaluable.

This does not mean a free ride for Dhoni till the World Cup. There are challengers —old and young—lurking to get his place in the side that he will be seized off. The best way to ward them off is to make your presence in the middle count.

Ayaz Memon is a senior columnist who writes on sports and other matters.