Marchant is only 20 but has made such an impression on England head coach Eddie Jones he is included in the Elite Player Squad (EPS) as the latest in a long line of Quins academy players to hit the big time.
Marchant, who played for England U20s, is getting a crash course in international midfield skills alongside Roberts, the Lions and Wales star, who describes the Winchester-born player as “a sponge”, who is absorbing lots of information.
Roberts, determined to hold onto his Wales midfield role in the Six Nations, has played in three Lions Tests and won 86 Wales caps and the 30-year-old said: “Joe is a bit of a sponge and has lots to learn. He is very quick to listen and work on his game which is great to see and what makes him pretty special is his footwork and outside break.
“He is very like Jonathan Joseph in his athletic ability and the way he plays the game. When you have someone like that as your centre partner then it is all about putting him into space and letting him work his magic.
“Joe has a lot of time on the ball, can beat an opponent in a square metre with his footwork and is a real talent who is on the right path and, hopefully, as a side we can get him into the England squad and full honours.”
Nick Evans, the former All Blacks No.10, has been helping with the backs coaching at Quins this season and has taken a close interest in the development of Marchant.
Evans agrees with team-mate Roberts that their young centre’s thirst for rugby knowledge will ensure he does not rest on his laurels or start to listen to the praise that is coming his way this season.
Evans said: “Putting a coach’s hat on, when you look at Joe you straight away say that he is an instinctive player – the kind of guy you don’t want to over-coach.
“You don’t want to give him too much structure and rein in what he is good at.
“If you give him the ball then it is about playing what’s in front of him; if there is space on the outside then give it a crack. If it is on to pass then let him make that instinctive decision.
“For someone that young and talented you cannot give him too many things to think about and the thing he needs to work on more and more is seeing the pictures in front of him.
“When he does that then it is about making this positive decisions not negative ones.
“Initially, he struggled a bit with the system we play, but has got better at that and defensively he is improving and it is fantastic to see how much he is learning. The more he grows, the better he gets.”
Roberts acknowledges that unlike other Home Unions, England are blessed with plenty of centres with head coach Eddie Jones able to opt for a number of different options with a cast list including: Joseph, Owen Farrell, Elliot Daly, Henry Slade, Marchant, Ben Te’o, Ollie Devoto and Manu Tuilagi – when fit.
Having been playing against them for Quins following his switch from Top 14 rugby with Racing, Roberts is well-placed to give a verdict on England’s strength in depth.
He said: “England have got a lot of options and can pick three or four players in each position from the Premiership. Wales, Scotland and Ireland don’t have that strength in depth.
“I am happy with my own form and I have to keep raising the bar with my performances and put my hand up for international selection. The selectors are always watching and you have to be consistent with your performances and it isn’t a case of being out of sight, out of mind playing in England.
“It is about going out there and trying to impress within the team collective.
“I have to prepare well enough every week as a Test match player. That’s the challenge.”
CHRIS JONES