Nick Faldo set off the golfing equivalent of a neutron bomb when he picked Ian Poulter ahead of Darren Clarke ... and the invisible fallout is likely to contaminate the European locker room at Valhalla.
Morale has already been impacted, though few, if any, dissenting voices will be raised in public. Loyalty to the cause, if not the captain, is all-powerful in European Ryder Cup circles.
Silence often speaks louder than words in professional golf, especially in the wake of Thomas Bjorn's spectacular and ultimately self-damaging rant against team captain Ian Woosnam after he'd been omitted from the team for The K Club in 2006.
For example, Clarke himself has been the soul of discretion since Sunday, accepting Faldo's hugely controversial decision with remarkable dignity.
Yet an insider revealed yesterday that, privately, Lee Westwood is livid at this appaling snub to his close friend and Ryder Cup playing partner.
And should one interpret Padraig Harrington's uncharacteristic failure to respond to texts and phone calls since Sunday as a message in itself?
Doug Ferguson, the chief golf writer at American news agency, Associated Press, painted an interesting verbal picture with his description of the scene as he caught up with Harrington at TPC Boston on Sunday evening.
Ferguson wrote: "British Open and PGA champion Padraig Harrington was cleaning out his locker at the Deutsche Bank Championship when he was asked for comment, and said initially he could not think of anything to say so soon after the (team) announcement.
"Two great players who will strengthen the team," he finally said of Casey and Poulter.
What's that they say about faint praise?
Harrington nailed his colours to the mast last week, when he said: "I can't see how you couldn't pick him (Clarke). He's won twice this year and, more importantly, his form's been very good in recent weeks."
On that occasion, Harrington readily accepted Faldo's opinion might be different to his own ... yet it's difficult to imagine many European Tour players feeling comfortable with Poulter's selection after his failure even to try and play his way into the Ryder Cup team at Gleneagles.
If anything, three-times former Ryder Cup captain Bernard Gallacher was understating the case when he said "I think the morale in the team might be a bit lower for picking Poulter ahead of Clarke ... There'll be a few players thinking, 'Nick, I think you've made a mistake."
If this mistake affects senior players like triple-Major Champion Harrington and Ryder Cup veteran Westwood, two people Faldo expects and needs to perform an influential role at Valhalla, the consequences will be serious for Europe.
In a straw poll of 32 European Tour players at Gleneagles last week, just one said he'd give Poulter a wild card. By doing precisely that, captain Faldo plainly has placed himself at odds with many of his peers on tour.
Colin Montgomerie got word of his omission at 6.40pm on Sunday evening when a voice message from Faldo popped up on his phone as he was driving.