O'Brien handed two-game ban
The former Bradford stopper was given his marching orders by referee Barry Knight for bringing down England international striker Darius Vassell in a goalscoring opportunity.
A professional foul would normally only incur a one-match suspension, however with the 24-year-old has already been dismissed this term - giving him an additional game.
O'Brien also saw red after 40 minutes in The Magpies' 5-0 reverse against Chelsea at Stamford Bridge for bringing down Adrian Mutu that resulted in a penalty kick.
United manager Sir Bobby Robson will now be without the strong defender for the visit of Wolves and their trip to the South Coast to play Southampton.
Meanwhile, a delegation from NAC Breda are set to travel to the North East to negotiate a possible link-up between the clubs.
The Magpies dispatched the Eredivisie side 6-0 on aggregate earlier this season in the Uefa Cup.
Talks had been on hold until the club appointed a new director of football, however Theo Mommers has now been given the job.
"Over the past few months we've already spoken with Newcastle on several occasions, but our trip this time will make things more concrete," he said.