Richie Rees has made nine appearances for the Blues this season
Cardiff Blues have decided not to appeal against the 12-week ban that ruled scrum-half Richie Rees out of Wales' 2011 Six Nations campaign.
Rees was banned for 12 weeks by an European Rugby Cup disciplinary hearing in Dublin on 6 January.
The Cardiff Blues man was found guilty of making contact with Northampton hooker Dylan Hartley's eye during their 23-19 Heineken Cup loss on 19 December.
Rees pleaded not guilty on the basis that any contact had been accidental.
But after looking into the possibility of an appeal, Rees has reluctantly accepted his fate and set his sights on the Blues' end-of-season run-in, in which he hopes to press claims for a place in Wales' World Cup squad for the autumn tournament in New Zealand.
"Having sought legal advice, with the support of the Blues and WRU [Welsh Rugby Union] we have decided not to appeal against the decision," said Rees.
"Naturally I am disappointed at the outcome of the hearing and to be suspended for 12 weeks. Missing out on the Six Nations and some crucial games for the Cardiff Blues is hugely disappointing and hard to accept.
"I felt it was worth looking at the possibility of an appeal as I am desperate to play for the Blues and Wales and naturally feel frustrated and disappointed at the outcome."
Independent ERC judicial officer Pat Barniscale found that the contact had been "reckless and not intentional."
The 27-year-old, who won the first of his nine Wales caps against England in February 2010, has been Wales understudy for British and Irish Lions star Mike Phillips so his suspension was also blow to coach Warren Gatland.
"It is disappointing and I looked at the incident and thought it was pretty innocuous," said Wales boss Gatland after the ban was imposed.
"It is a shame for him and a shame for Wales."
Commissioner Murray Whyte cited Rees "for acts contrary to good sportsmanship in contravention of law 10.4(m) in that Rees had made contact with the eye/eye area of Hartley 30 minutes into the first half."
Officer Barriscale reviewed evidence that included "several angles of the incident from television footage and medical statements" relating to the injuries sustained by Hartley.
Both Hartley and Rees gave evidence while the hearing also heard submissions on Rees' behalf from Blues chief executive Robert Norster and on behalf of ERC disciplinary officer Roger O'Connor.
Barriscale found the offence was "at the low end of the level of seriousness for an offence of this type."
Rees is free to play again on 31 March while his ban could herald a return to the Wales squad of Sale's 2005 Grand Slam scrum-half Dwayne Peel.
Rees' Blues colleague Xavier Rush was also shown the red-card in the defeat to Northampton, a loss that ended Cardiff's Heineken Cup hopes, and was punished with a one-week ban for a high tackle on Courtney Lawes.