Michael Vaughan feels Alastair Cook should stand down as England captain if he does not retain the same enthusiasm and energy for the job.
After England had suffered a second successive innings defeat on Tuesday to finish 4-0 series losers in India, Cook said he was in no state to make the call on whether he extends his four-year reign at the helm.
England do not play Test cricket again for more than six months, with South Africa their next opponents in July.
But former England captain Vaughan told BBC Radio 5 Live that Cook should "make the call sooner rather than later" and that it is "not healthy" to be away from the group for six months.
"He's got to have a real good think about it," Vaughan said.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Just ask himself 'have I got the energy to take this team forward?' The Ashes are in 12 months time.
"If the answer is just a one per cent 'no' then he has to step aside."
Cook - who will be 32 on Christmas Day - has been in charge of 57 Tests since he became permanent England captain in August 2012.
He plans to meet England and Wales Cricket Board director Andrew Strauss next month about the future direction of English cricket.
"Andrew Strauss has got to say to him 'Cooky, have you got the energy?" Vaughan said.
"You need to have so much energy to lead your country. You've got to be number one into that training zone.
"You need to be in that dressing room giving the right vibes. You have to walk on to that field full of positivity.
"Indian tours can drag anyone down. I think he said it himself that he feels the Test match team is stagnated and when you hear the captain saying those kind of words it is not too far they decide to go in a different direction."
"I am seeing in Alastair Cook a player who is not enjoying the game."
