Arsenal manager, Arsene Wenger, was found guilty of failing to abide by UEFA rules surrounding his original ban after he passed messages to the coaching staff at the Emirates Stadium in the first leg match last week.
UEFA claims Wegner was warned no to cotinue by match delegates at half-time. Arsenal, though, maintain officials from Europe's governing body had told them in the build-up to the game that Wenger would be permitted to relay instructions to assistant manager Pat Rice through first-team coach Boro Primorac, who was in telephone contact with the Arsenal bench.
UEFA also fined Arsenal 10,000 euros (£8,743) for the improper conduct of their officials during the match.
It remains to be seen whether Arsenal's appeal will be processed in time for a decision ahead of the second leg of the Gunners' Champions League qualifier against Udinese, which the Gunners lead just 1-0.
A statement from UEFA read: "The UEFA control and disciplinary Body has suspended manager Arsene Wenger from carrying out his duties at Arsenal FC's next two UEFA competition matches.
"Today's decision was taken in relation to the Arsenal manager not abiding by the decision of the control and disciplinary body during the English club's Champions League play-off game against Udinese last Tuesday, August 16.
"Wenger is therefore suspended for Arsenal's second-leg match against Udinese in Italy on Wednesday and then the next UEFA competition fixture for which he would be eligible.
"The control and disciplinary body has also decided to fine Arsenal 10,000 euros for improper conduct by its officials. An appeal may be lodged against these decisions within three days of the dispatch of the reasoned decision.
"The UEFA disciplinary regulations stipulate that manager may not communicate with his team during a fixture for which he is suspended and may follow the game from the stands only."
Because of the ban, Wenger decided against fulfilling his post-match media commitments, a pattern which he could well follow again at the Stadio Friuli should UEFA uphold their decision.
The news is the latest blow to the Gunners who are going through one of the toughest spells of Wenger's tenure.
Arsenal were beaten 2-0 at home by Liverpool on Saturday, when they were without Alex Song and Gervinho, both serving suspensions in the fall-out from the ill-tempered goalless draw at Newcastle. However, the duo will be available for the European tie, along with captain Robin van Persie, who was banned for the first leg after his red card in the Nou Camp.
Should Wenger again select contract rebel Samir Nasri, it would cup-tie the France midfielder and prevent him for playing with another team in the competition, as talk of a £22million switch to Manchester City continues.
Arsenal, though, could see midfielder Jack Wilshere return from his ankle problem, while Johan Djourou's recovery from a hamstring complaint could offset the loss of Laurent Koscielny, who hobbled off on Saturday following a back spasm. Spanish teenager Ignasi Miquel came on to make his Premier League debut against Liverpool.
The 18-year-old centre-half insists all is not yet lost for the Gunners. "We have to work hard and forget about this result," he told www.Arsenal.com. "Next week we have Manchester United and, firstly, Udinese in the Champions League. It is pointless to think about [the Liverpool] result.
"We have to be positive because Udinese have to score two goals. We have to be positive, give 100% and, if we do that, I am sure we can win it."
Arsenal, meanwhile, continue to be linked with a string of players, with Wenger said to be ready to spend the £30million received from Barcelona for captain Cesc Fabregas. Everton defender Phil Jagielka is reported to be on the Arsenal manager's shortlist, along with Rennes midfielder Yann M'Vila and Lille forward Eden Hazard.