Jones contacted Blackheath head coach Harvey Biljon asking if he could play a match and Biljon, having consulted the players and committee of the club who are celebrating their 150th anniversary this year, replied: “Yes, great.”

A crash course in learning the game will culminate in Jones “playing five or 10 minutes off the bench” against the Cornish All Blacks on Saturday, Biljon confirmed.

“Our players thought it would be fantastic to have a full-time athlete from a top American sport testing himself among our amateurs,” Biljon said.

“Because Dhani [pronounced Dee-hah-nee] is a defensive lineman, his catching and passing are the things we need to work on.

“All being well, he will come on the field as a flanker. I don’t think it will make much difference whether it’s blindside or openside.

“We just have to make sure that when he hits someone it is an opponent who has got the ball and that he’s not running an illegal blocking move.”

Jones is 6ft 1in and 240lb, and has had eight NFL seasons, playing for New York Giants, Philadelphia Eagles and New Orleans before joining the Bengals last September. He was second on their tackle list for the season just completed. He started Super Bowl XXIX for Philadelphia in 2004.

The 29-year-old from Potomac will have had three rugby training sessions at Blackheath’s Rectory Field before Saturday, and also paid a visit to Leicester’s Premiership match against Newcastle last weekend, when he was hosted by former Tigers and England stars, Martin Johnson – a huge NFL fan – and Austin Healey.

“It is all good fun and there is no disrespect to the cup,” Biljon, the former Wasps and Natal scrum-half, said.

“Launceston are pretty much semi-professional and I think they will fancy fronting up against Dhani. That’s the natural competitive spirit, which is what the cup is all about.

“We are in the top four of National Division Two and Launceston are near the bottom of National One so this match will give us an idea how we need to prepare and improve if we get promoted.”

The EDF Energy National Trophy is the premier second tier cup competitiion in England and runs alongside the showpiece EDF Energy Cup and also the EDF Energy Intermediate Cup, EDF Energy Senior and Junior Vase.