Ireland head coach Andy Farrell says Cian Healy's leg injury "does not look too good".
Healy was helped off the pitch on a medical cart during Ireland's 32-17 defeat by the Maori All Blacks.
The veteran prop came on as a replacement early on during the game for Jeremy Loughman, who temporarily went off for an HIA.
If neither is available for Saturday's opening Test against New Zealand it would leave Ireland with just one fit loose-head prop - Andrew Porter - in their touring squad.
"Cian Healy does not look too good... he was in a bit of pain coming off the field. [The injury] has settled down a bit so we will have to see with him," assessed Farrell after the match.
James Hume and Jimmy O'Brien were also unable to finish the match due to injury.
"Jimmy came off with a strain. He's feeling pretty good in the changing rooms.
"Jeremy actually passed his HIA with an independent doctor. We brought him off as a precaution. James has a bit of a groin injury that needs assessment tomorrow."
Farrell reflected on the defeat saying: "We're disappointed,"
"We know it was a big week for the Maori boys but it was a big week for some of our guys, playing for Ireland for the first time.
"There was really good stuff from certain individuals but a lot of dumb stuff along the way.
"It was brilliant as far as our learning is concerned because that's what you've got to iron out if you want to make it to the top."
If Healy and Loughman are unavailable to Farrell for the first test match, Andrew Porter may need to go the full 80 minutes. Finlay Bealham can also cover at loosehead but is a recognised tighthead prop.