Wales will play Ireland in the Millennium Stadium on Saturday (kick-off 2.00pm)
The 34-year-old Bath hooker claims he is "100% confident" of recovering in time to face the Grand Slam chasing Irish.
Humphreys was a pivotal figure in the positive Wales performance against England, having been brought back from the international wilderness by Steve Hansen.
"I am fine in myself, and more or less definite to make it," said Humphreys, before embarking on a three-day training camp with the Welsh squad in Tenby.
"In my own mind, I am 100% confident of being fit."
Pontypridd hooker Mefin Davies is the most likely candidate for the shirt should Humphreys be unable to play.
With injuries to hooker Robin McBryde, Barry Williams, Andrew Lewis and latterly Gareth Wales coach Steve Hansen's option are limited.
Swansea's 19-year-old unknown Huw Bennett's name has been mentioned as a possible candidate for an international call up.
Bennett is highly-rated by Hansen, and the Wales coach said: "He has got a bit of the x-factor about him.
"He is going to be a very good player in the future and he has been working with us now for most of the time over the last 12 months," added Hansen.