A real shame for the Athlone native.
So late that an IRFU official had to make the change in black pen, Robbie Henshaw's name was struck from the Ireland team to face Argentina with only minutes to go before kick-off.
The Leinster centre took part in the pre-match warm-ups but, after discussions with the Ireland medical team, it was decided to pull him from the matchday 23.
Ulster's Will Addison was drafted into the squad and went straight in as No.13. Addison only made his Ireland debut against Italy last week and this was his first start.
Henshaw looked crestfallen as he hobbled from the pitch, 15 minutes before kick-off, and the IRFU later confirmed he was pulled from action as a precaution for "tightness" in his hamstring.
Henshaw missed out on the trip to play Italy in Chicago but did play a full 80 in the Gunness PRO14 win over Treviso on October 17.
Joe Schmidt is give little away in his post-match assessment but Henshaw must now be a doubt to face New Zealand in Dublin next Saturday.
