The Gloucester second row, who made his international debut against the All Blacks in November, has been suspended for stamping.
Attwood was handed a nine-week suspension on Thursday afternoon backdated to the day of his offence, ruling him out of action until February 21, two-and-a-half weeks after Wales look to get their campaign off to a flying start against Martin Johnson's men.
The 23-year-old former Bristol player was cited following Gloucester's Amlin Challenge Cup clash with La Rochelle at Kingsholm on December 19 after an incident involving opposition prop Petrisor Toderasc.
Attwood was found guilty of foul play in contravention of Law 10.4(b), with the independent judicial officer initially recommending a sentence of 18 weeks. He then reduced this by 50 per cent after taking into consideration Attwood's guilty plea, clean record, clear remorse and exemplary conduct at the hearing.
Attwood has impressed for his country since touring Australasia in the summer and was expected to be a contender for at least a spot on the replacements bench at the Millennium Stadium.
Tom Palmer and Courtney Lawes have established themselves as England's first-choice lock pairing but Attwood was vying with veteran Simon Shaw for the first back-up slot.
Johnson is expected to name his 32-man Six Nations squad on January 12.