New Delhi: Finally, we can confirm the reason why Indian cricket selectors ignored veterans Yuvraj Singh and Suresh Raina for the upcoming limited-overs series in Sri Lanka. After all, both the players can still do magical things and win matches single-handedly for India.

And in certain sections of media, their age was cited as the reason for the snub. But on Wednesday, a clearer image emerged with reports claiming that poor fitness which proved detrimental to their selection.

READ: What is Yo-Yo fitness Test that Yuvraj Singh, Suresh Raina failed ahead of ODI squad selection?

A PTI report claimed that the failure to clear the 'Yo-Yo' endurance test at the National Cricket Academy was the primary reason why Yuvraj and Raina were not considered for the Sri Lanka limited overs series.

It's also worth noting that after Sunday's team announcement, both the selection committee chief MSK Prasad and head coach Ravi Shastri have stressed on the need to have a supremely fit team as Virat Kohli & Co embark on a journey with the sole motive to conquer the world in every format of the game.

In an interview with the TOI, Shastri had indeed said that "only the fittest of the lot will survive and thrive going forward and that's right up there in the list of priorities."

The PTI report claimed that the acceptable 'Yo-Yo' score is 19.5 and upwards for the current Indian team, even though skipper Kohli easily scores around 21 in the test. However, both Yuvraj and Raina have scored well below this permissible level, with Yuvi barely managing to touch 16.

Couple it with Yuvi's recent poor form, most importantly in the ICC Champions Trophy in England, selectors have got no other option but the ignore the two-time World Cup winner and one of India's biggest match winners in limited-overs. Raina's was also more or less similar. The T20 specialist was looking for a comeback after a long lay-off, but with poor fitness, he had got not chance to make the team, which is now considered one of the fittest around.

"The current team think tank, coach Ravi Shastri, skipper Virat Kohli and chairman of selectors MSK Prasad have made it clear that fitness standards are non-negotiable.

"On an average, the Australian cricketers score 21 in Yo-Yo test. Here Virat, Ravindra Jadeja, Manish Pandey regularly hit that score while others are either touching 19.5 or is hitting above that score," PTI reported an unnamed BCCI official as saying.

"In an earlier era, when the traditional beep test was in vogue, the Indian players of the 1990's would have scored around 16 to 16.5 barring a few like Mohammed Azharuddin, Robin Singh or Ajay Jadeja.

"But now it's different as the skipper himself is hitting the benchmark, which the Australian cricket team sets it," the official added.

What is 'Yo Yo' endurance Test and how does it works?

Like other professional sports teams, Indian team also regularly undergoes a series of fitness tests with 'Yo-Yo' endurance test being the most important of them. 'Yo Yo' is an advanced version of the 'beep' test that was used by teams of earlier generations.

Cones are placed to mark out two lines 20 meters apart. A player starts with his foot behind one of the lines, and begins running when instructed. Player continues running between the two lines, turning when signalled by the recorded beeps.

After each minute or so, the pace gets quicker. If the line is not reached in time, the player must run to the line turn and try to catch up with the pace within two more 'beeps'. The test is stopped if the player fails to catch up with the pace within the two ends.

The entire process is software-based where the results are recorded.

(With PTI inputs)