Prop Cian Healy has suffered an injury scare on the eve of Ireland's World Cup squad announcement during an unconvincing 17-13 success over Samoa in rain-soaked Bayonne, France.
Healy was helped from the field in obvious discomfort less than 24 hours before Andy Farrell names his final 33-player selection for the upcoming tournament.
Despite Jimmy O'Brien's early try, Ireland trailed at the break in their final warm-up fixture, before battling back to scrape a 13th straight win thanks to further scores from Conor Murray and Rob Herring.
But the result at a sold-out Stade Jean Dauger could come at significant cost after Healy, who departed just 21 minutes into his 125th Test, added to Ireland's front-row concerns.
"It's his calf so there's something going on there but rather than guess we have to take a picture and see how it goes," Farrell said after the match.
"We'll get him back to Dublin and get him scanned and we'll know soon enough."
Farrell's planning has already been complicated by ongoing injury issues for Healy's fellow loosehead Dave Kilcoyne and hookers Dan Sheehan and Ronan Kelleher, although he expects the trio to be available in the coming weeks.
The head coach, whose side begin their World Cup on September 9 against Romania in Bordeaux, was also forced into a change ahead of kick-off as a niggle for wing Keith Earls afforded a chance to Jacob Stockdale.
A fine Murray tackle denied Samoa an early lead before Jack Crowley's pinpoint cross-field kick allowed Mack Hansen to gallop down the right wing and give fullback O'Brien a simple finish for his maiden Test try.
Physicality was at the forefront of this encounter and Farrell's men suffered a setback when the hobbling Healy was assisted off the pitch by medical staff and replaced by Jeremy Loughman.
Ireland ended the half 10-7 behind after Duncan Paia'aua intercepted a Stuart McCloskey pass inside his own half to brilliantly race clear and dive over, before Lima Sopoaga added the conversion and a subsequent penalty.
Samoa were facing a tier-one nation for only the second time since losing 47-5 to Ireland at the 2019 World Cup.
A second penalty from former All Black Sopoaga stretched their lead early in the second period before Stockdale's kick over the top was gleefully dotted down by the diving Murray, albeit Crowley's wayward conversion left Ireland a point behind.
The world's top-ranked side finally regained the lead 17 minutes from time when replacement hooker Herring bulldozed over from a line-out maul.
Roared on by the mostly French crowd, Samoa refused to roll over and continued to cause problems.
But on a day when Fiji stunned England at Twickenham, they ultimately fell short of producing a further major shock as Ireland survived a significant wake-up call.