Ireland flanker Alan Quinlan has been banned for three weeks after being cited for stamping in the 22-3 defeat by New Zealand on Saturday.
All Blacks prop Tony Woodcock was also cited on a charge of striking but was cleared and is free to play against Wales this weekend.
Quinlan, whose ban will end on 7 December, has the right of appeal.
The Munster back row's ban would appear to leave Ulster's Stephen Ferris in line to play against Argentina.
Quinlan was cited for a stamp on All Black number eight Rodney So'oialo in the Croke Park defeat.
Referee Mark Lawrence spotted the incident yet only cautioned the 34-year-old and allowed a penalty against New Zealand to stand.
Citing officer Peter Larter decided the stamp warranted further scrutiny and International Rugby Board disciplinary officer Lorne Crerar said Quinlan should have been red-carded, and imposed the suspension.
All Black Woodcock, who was sin-binned for a punch just after the break, admitted foul play but escaped further action.
Ireland play the Pumas on Saturday while New Zealand, who edged Irish province Munster in midweek, will take on Wales in Cardiff.
Ireland coach Declan Kidney will name his team on Thursday.
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