Four-time Five Nations Champion Will Carling, 48, has waded in on the debate that has engulfed the football industry.
Yesterday, England manager Roy Hodgson admitted that fleet-footed 19-year-old Raheem Sterling's admission that he "was too tired to start" was a key reason why the Liverpudlian began the match against Estonia on the bench.
Sterling played 25 minutes of professional football on Sunday and his introduction ended up changing the game, however, pundits like Robbie Savage and Stan Collymore both scoffed at the claim that a professional footballer could be tired.
While fitness expert Raymond Verheijen claimed the outrage over the 'issue' highlighted England's status as a third world football country.
For Will Carling, it is a situation that is not exclusive to football.
He said: "[I am] always amazed how simplistic some people are. Professional sportspeople can never get tired/ lose form. They get paid! They are still human!
"I am not just talking footy with the last tweet. Sometimes the adrenaline is just not there. The extra edge. [This can be] down to opposition, or fatigue."