Maro Itoje says that England and Saracens team-mate Owen Farrell is a "phenomenal" captain who brings out the best in those around him.
Farrell has come under pressure after England finished fifth in the Six Nations, suffering defeats by Scotland, Wales and Ireland.
"I have known him since I was 11 and been fortunate to be very close to him," said Itoje.
"I am fully 100% behind Owen. He's a great player, friend and captain."
Itoje added: "I have seen how he operates, how he thinks, gets the best out of himself and how he motivates people around him.
"I think he is a phenomenal captain. If you look at what he has done with England and with Saracens, he has led the team to some brilliant things."
Itoje has been mentioned as a potential candidate to take on the role should Farrell, who head coach Eddie Jones has said is still 'learning' about captaincy, be replaced.
However the second row, 26, said he was unsure who took on captaincy duties when Farrell was forced off with a head knock in the 55th minute of the 32-18 defeat by Ireland on 20 March.
"Erm…Good question," he replied when asked who stood in during Farrell's absence.
"I am not even too sure, if I am going to be honest with you. There was a bit of chatter, but, hand on my heart, I can't give you a definitive answer."
Itoje, who lifted the world junior title as England under-20s captain in 2014, is philosophical about his own prospects of one day leading his country at senior level.
"If you are clamouring to be captain or campaigning to be that is not the right thing to do," he added. "You are wanting it for selfish reasons.
"If that happens, it happens. It is not something that keeps me up at night."
Source: BBC Rugby Union News