Will Greenwood has backed the appointment of Dr Sherylle Calder, who will reprise her role as England's visual awareness coach.
Eddie Jones has confirmed that Calder will be part of England's backroom staff during the Six Nations and through to the 2019 World Cup.
Sir Clive Woodward first signed her up when England won the Rugby World Cup in 2003 and she was also part of the South Africa staff when the Sprinbgoks won the 2007 World Cup.
Greenwood, who was part of the World Cup winning team in 2003, cannot speak highly enough of Calder and explains exactly what she will add to England.
"She used to be my favourite pub quiz question - until New Zealand peskily came along and ruined it," joked Greenwood on Sky Sports News HQ.
"The All Blacks won back-to-back World Cups in 2011 and 2015 but before that there was only one person in men's rugby who had won back-to-back World Cup medals!
"Sherylle won the World Cup in 2003 and then Jake White called her up and asked her if she wanted to come home - she's South African - and she went and worked with South Africa and guess who won the World Cup in 2007?
"She didn't score a try, she didn't make a tackle and she didn't kick a drop-goal but you ask Jonny Wilkinson about her, you ask Bryan Habana about her and they will go wow - she is fantastic.
"Big Ernie Els has worked with her and sings her praises, the cricket boys - Andrew Strauss and co have worked with her. She is working down in Bournemouth with Eddie Howe.
"You can go to the gym and train your biceps and your quads - but the eye is also a muscle and you can increase the ability of your eye to move faster and to see more in your peripheral vision and opens your eyes to opportunities out in the field.
"The classic thing to do on a Monday is look back and say that they missed this chance or that chance. What Sherylle equips you to do is see those chance on the day and fix it on the day."
Greenwood added: "She gave us a little acronym - CTC. Which stood for Crossbar, Touchline and Communicate.
"So keep looking up at the crossbar in front of you, keep scanning the touchlines and keep communicating the space.
"I am a massive believer in finding marginal gains and Sherylle is a fantastic marginal gains and will work with the team until 2019 and will, open their eyes to the space and opportunity on the rugby field."