It is a saturated Sunday in late October at Welford Road and his Leicester side are a single point to the good in their Pool Four Heineken Cup meeting with the reigning European champions.
Jennings has only been on the pitch since the 61st minute as a replacement for Lewis Moody but within 60 seconds he has conceded a penalty from which Ronan O’Gara kicks the visitors into a nine-point lead.
Not ideal but fast forward 20 minutes and the Tigers have turned it around. They lead by a single point. The rain is pouring down with the ferocity of an Asian monsoon but Leicester are grimly holding out.
There seems little cause for concern when they concede a penalty ten yards inside the Munster half but then Jennings makes an ill-advised remark to Welsh referee Nigel Owens and suddenly O’Gara is lining up a shot at goal from just inches beyond the halfway line.
Criticised all week for his forthright views on the English Premiership, the Irish out-half provides the perfect riposte by squeezing the pill over the crossbar, leaving Jennings to curse his unwitting role in the home side’s downfall.
Shane, what were you thinking?
“I’m still hugely disappointed that I gave Ronan the opportunity to get that kick,” the 25-year old explains. “I take the blame. I fully accept it.
“It was very tough to take. It’s just one of those things. It’s history. Old news.”
It has often been said of Munster that a team may beat them once, but no-one ever triumphs over them a second time. The same could be said of Leicester at Welford Road but that’s exactly what Munster have now done.
Jennings takes the point and admits that the English side travel to Limerick this weekend feeling they owe Declan Kidney’s side one.
Yet, strangely for a man who played 43 times for Leinster in four seasons and who has represented Ireland at Schools, U19, U21 and ‘A’ levels, he has never played at Thomond before.
Even while on AIL duty with St Mary’s, the opportunity never presented itself to take on Shannon in Thomond. Though respectful of the ground’s patented mystique, he speaks confidently of the challenge awaiting the visitors there.
“They’ve obviously got a fantastic support and they will be vocal and try to intimidate. That’s fair enough. They’re there to back their team. Then again, they’re not the ones playing.
“Your focus has to be on the lads facing you on the pitch and if you can block out what’s happening in the stands that’s going to help. It will be a new experience for me and a lot of the guys but it is just something we will have to cope with.”
With Thomond closing its doors for a lengthy spell in the near future, he won’t be returning any time soon but the decision to return to Leinster this summer means he will be meeting Munster with some regularity again over the next three years.
Named Leicester’s players’ player of the year last season, the Tigers will be sorry to see him leave but the feeling will be mutual as he admits to enjoying his two-year stint in the midlands more than he imagined he would.
“Irish people have this perception of what English people are like but they have been nothing but brilliant to me. They have made me feel so welcome and it’s no different to home.”
He has revelled in the weekly grind that is professional rugby in England.
“All rugby players want to do is play games. It’s no different over here. Every game is a pretty big game. Newcastle would be perceived over here as one of the weaker teams and when we went up there they turned us over.
“If you’re not on your mettle every time you won’t get a result. That’s what I wanted. I wanted games.”
Playing in the Magners League, his diet will be trimmed somewhat in that regard but he will hope to make up for it by feeding at the top table with Eddie O’Sullivan’s Irish squad.
Though captain of the Irish ‘A’ side that won the plate section of last year’s Churchill Cup, Jennings was again omitted when the 35-man squad was announced for this year’s Six Nations on Tuesday.
“If you’re at home and get into a provincial side, then you’ve as much right as anybody to knock on the door. It’s obviously a motivation.”
Not that any more will be required after what happened the last time these sides met.