Dublin - British and Irish Lions coach Warren Gatland has warned his captain for the tour of New Zealand won't be assured of a place in the Test side.
Gatland, the Lions' coach on their victorious tour of Australia four years go, will take charge of the combined side again for a three-Test series against world champions New Zealand in June and July after once more being seconded from his 'day job' in charge of Wales.
The New Zealander is due to reveal his squad and skipper on April 19.
Conventional rugby wisdom has it that a Lions captain must first be a nailed-on certainty for the Test side.
That has led to speculation that in additon to the four Home Nations captains, Wales's Sam Warburton, the Lions captain in 2013 but no longer skipper of Wales, and England goal-kicking centre Owen Farrell could be considered for the honour given their likely inclusion in the Test team.
But Gatland appears to be contemplating the possibility of a 'tour captain' instead as the Lions seek just a second series win in New Zealand to go alongside their 1971 success.
"I think the captaincy is a great honour, but whoever the captain is going to be there'll be no guarantee he plays in the Tests," Gatland told BBC Radio Five Live on Sunday.
"His form has to be good enough. I think whoever that person is has to rise to that, the message to that person is it's a great honour to captain the Lions but your form has to be good enough to be selected for the Tests."
Gatland, a former Ireland coach, added: "For the other players in that position I'll be having the same conversation as well.
"You say 'if your form is good enough and you play better than the captain, then there's every opportunity you can play in the Tests'."
But Clive Woodward, a former Lions coach, held to the view that the captain must be a nailed-on Test player.
On that basis Woodward, in charge for the Lions 3-0 series loss during their last New Zealand tour in 2005, said Warburton should captain this year's side.
"You need one person who is going to be in the Test team without a shadow of a doubt, a Brian O'Driscoll, a Martin Johnson, a Lawrence Dallaglio type of figure," said Woodward, England's 2003 World Cup-winning coach.
"Personally I have always been a huge fan of Sam Warburton, he knows Warren well, he's been a successful Lions captain already.
"Would he be in the starting team? Absolutely, the first name on the sheet," added former centre Woodward, who made two Test appearance for the Lions on their 1980 tour of South Africa.
Gatland, asked about Warburton's chances of leading the Lions in New Zealand, said: "He's a different captain to some other players, he leads by example. He doesn't say a lot but he has that experience.
"He's one of the guys in contention, definitely. In my mind there's probably half a dozen people in contention."
That list should include Ireland captain Rory Best, who outplayed opposing skipper and hooker Dylan Hartley in a 13-9 win that denied England a Six Nations Grand Slam in Dublin on Saturday.
Ireland coach Joe Schmidt, like Gatland a New Zealander, asked if Best should captain the Lions, said: "My choice doesn't count for anything, so I don't really express it.
"I'm incredibly proud of him (Best) and the way he leads the team. I'm delighted he's our leader."