England Test captain Joe Root has shrugged off suggestions from Australia legend Shane Warne that he should relinquish the captaincy to concentrate on his batting.

The outspoken Warne recently suggested Root should stand down from his position and allow Jos Buttler - who the Australian worked with in his role as mentor for Indian Premier League team Rajasthan Royals - to step up as Test captain.

Warne acknowledged that Root was England's best Test batsman, but felt he could be even better if he allowed a teammate to takeover the top job and captain the side.

"Maybe England could think about their best player having the shackles off, not having the responsibility of captaincy, and give it to someone like Jos Buttler," Warne said last week.

"If he (Root) totally 100 per cent concentrates on his cricket, his batting and nothing else, then maybe we might see Joe Root become the best batsman in the world. He's got the talent to do it."

But Root didn’t buy into Warne's comments, pointing to the fact that England recently defeated India 4-1 at home and have improved as a Test side since he took the captaincy reins from Alastair Cook in the middle of last year.

"They (Warne and Buttler) obviously have a really good relationship from Rajasthan and he's obviously a big fan of Jos ... and so am I!" Root told reporters in Sri Lanka.

"That’s why he's vice-captain and back in the Test side. He has played a vital role in our success this summer. I can understand why he's said that.

"I feel like I have done some good stuff and made some big strides in the way we have played during those five Test matches (against India).

"I feel like I have developed a lot as captain and this is a good opportunity to expand on that and try and deliver a strong series win away from home against a good side their own conditions. There will always be questions marks about captaincy and who is the right person to lead – I suppose this is the first time in my captaincy it's come up but I am quite comfortable with where we are at as a team and my role in that."

Root said playing 50-over cricket under England one-day captain Eoin Morgan had helped him immensely as he continues to mature as a leader in the Test arena.

"You are always thinking, looking at surfaces, grounds, opposition, the challenges that might be thrown at you, what's the most successful way of going about things and trying to figure that out early." Root said.

"I am always (trying to learn from Morgan). He is very relaxed and he has a very unique style. He is never flapping or flustered. He is very much in control all the time.

"In limited overs cricket to have that mentality and aura about you to the rest of the group under pressure situations is invaluable. It spreads confidence with the group. That is one of his huge strengths as captain and it could be an area where I look to improve myself. More than anything you tried to read how he goes about things as a whole. How he delivers his talks, how he interacts with individuals, weighs up difficult situations and delivers."