Newcastle have lost their appeal against Sebastien Bassong's dismissal on Saturday, the FA have confirmed.
The 22-year-old Frenchman was shown a straight red card by referee Howard Webb after tangling with Fulham striker Diomansy Kamara.
Bassong will now miss the club's final Premier League game of the season at Aston Villa on Sunday.
Because it was his second red card of the season, he will serve a two-match ban with immediate effect, ruling Bassong out of the first game of the 2009-2010 campaign as well.
Bassong was red-carded 60 minutes into a potentially pivotal game for the Magpies with his side trailing to Kamara's first-half strike.
The incident came just 10 minutes after Webb had chalked off a Mark Viduka header which would have levelled the scores and sent the Tyneside club to Villa Park sitting just outside the relegation zone rather than inside it.
A draw against Villa would keep Newcastle in the top flight providing Hull lose at home to Manchester United - although they would have to win if the Tigers got a point.
A victory for Phil Brown's men would ensure they finished above the Magpies regardless of what happens at Villa Park.
A statement from the Football Association read: ''At a regulatory commission hearing today, a claim for wrongful dismissal by Newcastle United defender Sebastien Bassong was rejected.
''Bassong was sent off during Newcastle United's Premier League match with Fulham on Saturday 16 May for denial of an obvious goalscoring opportunity.
''Bassong's two-match suspension, due to it being his second dismissal of the season, begins with immediate effect.''
Meanwhile, Michael Owen could feature for relegation-threatened Newcastle in their final game of the Premier League season.
The former Liverpool and Real Madrid striker, 29, was unavailable for last weekend's defeat to Fulham after sustaining a groin injury in training but could be ready to play some part against Aston Villa on Sunday.
Magpies boss Alan Shearer told the club's official website: ''He had a scan on Monday and there is no serious injury so we're hopeful he'll be involved on Sunday.''
Newcastle go into the match third from bottom and on the brink of slipping into the Championship, with Middlesbrough, Hull and Sunderland also in danger of joining already-relegated West Brom.