Martin O'Neill has admitted he would have found it strange to play a formal international against Northern Ireland because of his background.
The Derryman is looking to use today's behind-closed-doors training game to boost the fitness levels of rusty squad members.
O'Neill, who captained Northern Ireland at the 1982 World Cup, says that a desire for experimentation beyond normal friendly rules is the reason for putting up the shutters.
However, he acknowledged that a full international would have been an unusual experience for him because of his own journey.
"If it was a proper game, yes, I would maybe find that really strange. Really strange," said O'Neill, who will speak with his counterpart Michael O'Neill to agree a format for the match.
It's possible the exercise will be split into three 30-minute periods as opposed to two halves.
"Certainly, all the players here will be involved at some stage," said O'Neill, who has injury doubts hanging over Jonathan Walters and Wes Hoolahan heading into the weekend friendly with England. They will undergo scans on knee injuries.
"Primarily, the game will be to do with fitness," stressed the 63-year-old after a vigorous open training session at the venue.
"Some of the Championship players who've not played for a little bit were blowing a bit towards the end which was understandable. It (closed doors) allows me to try formations and stuff like that but generally speaking it's about fitness."