Rugby World Cup 2015: Ireland flanker Sean O'Brien banned for Argentina quarter-final

Sean O'Brien has escaped becoming the third Ireland player to be ruled out for the remainder of the Rugby World Cup, being banned for just one week by World Rugby for a punch on France lock Pascal Pape. O'Brien will miss the quarter-final against Argentina on Sunday 18 October but is available thereafter should Joe Schmidt's side progress.

O'Brien was cited after being caught by television cameras striking Pape seemingly without being provoked. The 28-year-old was facing a two-week ban, however his remorse and previous disciplinary record saw the punishment halved by the governing body.

The loss of O'Brien comes after captain Paul O'Connell and fellow back-row forward Peter O'Mahony were both ruled out for the rest of the tournament with hamstring and knee problems respectively. Fly-half Johnny Sexton is also a doubt with a groin injury after he limped off during the 24-9 win over France.

Last eight opponents Argentina will also be without a player due to ill-discipline after centre Marcelo Bosch was suspended for the game at the Millennium Stadium after a tip tackle on Namibia's Theuns Kotze during the 64-19 win at the Leicester City Stadium. Bosch will also be available for the semi-final and beyond should the Pumas beat Ireland.

Scotland's task of reaching a first semi-final at the showcase tournament for 24 years against Australia has been made tougher after rugby's governing body confirmed that forwards Ross Ford and Jonny Gray have been ruled out of the rest of the tournament. The pair lifted Samoa's Jack Lam during a ruck in the 36-33 win at St James' Park, which confirmed their place in the knock-out stage, but the offence has led to an unprecedented three-week punishment that curtails their involvement in the competition.

"We are disappointed by the outcome of today's discipline hearing, and subsequent suspension of Ross Ford and Jonny Gray," a statement from Scotland Rugby read. "We will consider carefully the full written judgement of Judicial Officer Christopher Quinlan QC before making a decision on any future action."

The ruling is the latest in a long line of controversial judgements made by World Rugby during the tournament, which has included Samoa's Alesana Tuilagi being given an initial five-week ban – which was subsequently reduced – after catching Japan's Harumichi Tateawa with his knee. Australia openside Michael Hooper escaped with just a one-week ban after he went shoulder first at Mike Brown, while England's Tom Wood was unpunished after kicking Wales' Liam Williams in the head.