Whelan confident Green will display his true colours
Glenn Whelan's feistiness for the fray should never be underestimated. His no-nonsense upbraiding of professional colleagues in the workplace has been well documented.
Abdoulaye Faye, for example, no longer dares to slack around his Stoke City team-mates and you guess he won't start a scrap with the spirited Dubliner again.
So it is that Whelan is well-placed to assess the merits or otherwise of the latest overnight sensation of Irish football, Derby midfielder Paul Green.
"We have crossed paths a few times going back the years, we've had a few little barneys I would say," offers the smiling assassin, recalling a Yorkshire derby between his then employers Sheffield Wednesday and Green's Doncaster Rovers.
"Yeah, at the time I think we were League One, I had just moved to Sheffield. It was like a local derby game as well which helped spice things up. I think he hit me once which I felt was over the top a little bit, but I haven't got him back ... yet! I'll try soon!"
Green will have already felt the clanking of Whelan's studs during training this week; both men are destined to start in Yerevan tomorrow, upsetting the midfield synchronicity of the last campaign, where Whelan dovetailed so neatly with the now injured Keith Andrews.
Lest we forget, Whelan and Andrews were themselves effectively international virgins before their partnership developed; it is a measure of Whelan's own accelerated development that he is now being asked to assess the merits of another fledgling.
"You can tell with Paul," adds the 26-year-old, "especially knowing him and playing with him a bit that he always had the ability to kick on and do really well. Then he got his move to Derby which has helped him come on leaps and bounds.
"He is playing for a big team and is doing really well for himself. Keith won't be there on Friday but it's not about individuals. Obviously for Keith it is disappointing but it gives someone else a chance to get in and do well.
"If that's the case then Keith might have to fight to get back in, but that's good to have in any squad. It just makes people try to improve and do better when they do get a chance."
Whelan's dramatic rise to prominence under the trusting eye of Giovanni Trapattoni is a prime example of that maxim; his stunning, albeit fortuitous, finish in Mainz against Georgia kick-started his career and Ireland's last qualifying campaign.
The senior man in the middle, Whelan admits there "will be a few things said to him during the week if he's selected. But knowing Paul, the way he is, he'll just take it like any other game and it won't affect him."
Like Green, Whelan will abandon his normally fluid club position to adopt the rigid holding style deployed by the cautious Italian. Accused of being tired by his club manager, Tony Pulis, the west Dubliner demurs. "That's probably the wrong word."
Stoke's poor start to the Premier League season hasn't altered the peculiarly Irish trend that sees an international regular struggling to break into a moderate club team.
As Whelan looks forward to his second qualifying campaign, now an established regular, it is instructive to recall just how easily he has slotted into the set-up, notwithstanding the obvious concerns that he is slave to the system.
Since then, both his and the team's expectations have risen exponentially.
"It was different for me back then as I was only just coming on the scene," he explains. "I knew the lads but didn't really. I knew them by name but now I can class them as friends and people I would speak to a lot. We have been together for two years now and hopefully we can improve and qualify this time.
"There are more expectations and I think we need to win on Friday. If we are looking to qualify and get out of this group, these are games that we should be winning and need to win. We have never gone into a game looking for a draw."