Arsene Wenger was baffled by an "unbelievable" red card for Aaron Ramsey in Tuesday's goalless draw against Besiktas in Istanbul.
Wales midfielder Ramsey will miss the second leg of the Premier League club's UEFA Champions League play-off with the Turkish side after being shown a second yellow card for pulling Oguzhan Ozyakup's shirt 10 minutes from time.
It was the first time the midfielder had seen red in his club career and Arsenal manager Wenger felt the decision from Serbian referee Milorad Mazic was extremely harsh.
"Both yellow cards for Aaron Ramsey are unbelievable," he told ITV. "When you see the fouls they have made it's not serious. Just not serious."
Arsenal were not at their best, but almost snatched a winner when substitute Alex Oxlade-Chamberlain's late shot was tipped onto the post by Besiktas goalkeeper Tolga Zengin.
Frenchman Wenger, who also lost midfielder Mikel Arteta to injury, is optimistic that his side can progress into the group stage for a 17th consecutive season by winning the second leg at the Emirates Stadium next Wednesday.
"It was a difficult game played at a frenetic pace from the first minute to the last." he added.
"We could have won it but they had chances as well, in the first half alone. In the end we didn't lose and hopefully we will make it at home."
Wenger was also encouraged by another assured performance from recent signing Calum Chambers at the heart of his defence.
He said: "I think he was once again very good and very convincing in his performance. He coped with the pressure, won the challenges and played on a pitch that was not easy. He did very well."
|Coach: S. Bilić|
for O. Şahan 73'
for O. Özyakup 81'
for M. Pektemek 88'
|UEFA Europa League Preview: Brondby and Slovan to protect handsome leads|
|Bentaleb pens new long-term deal at Tottenham|
|Barca agree Turan deal|
|FIFA bans Mayne-Nicholls|
|United States v Honduras: Klinsmann demands improvement ahead of Gold Cup opener|
|CONCACAF institutes extensive reforms in wake of FIFA corruption scandal|
|Mauri completes Milan move|
|City sign Turkey striker|
|Women´s World Cup final draws huge US TV ratings|
|My first Chelsea team better than current crop - Drogba|
|Bertrand set for lay-off after knee surgery|
|New five-year Juve deal for Marchisio|
|Allegri extends Juve contract|
|Koeman reiterates Alderweireld interest|
|Valencia bag Bakkali|
|New York City FC complete Pirlo capture|
|Panama v Haiti: Collat ready to challenge the best of CONCACAF|
|UEFA Champions League Preview: Harrison eyes TNS progression|
|FIFA sanctions Yemen for fielding ineligible player|
|Toulouse rubbish Ben Yedder exit reports|
|Mourinho ´knows what he´s doing´ with Falcao signing|
|Watford shell out club-record fee for Capoue|
|Braafheid signs Lazio extension|
|Nani finalises Fenerbahce move|
|Liverpool confirm O´Driscoll appointment|
|Liverpool have to start better - Lucas|
|USA simply too good - Sasaki|
|Portland Timbers 1 San Jose Earthquakes 0: Jewsbury wins it in stoppage time|
|No move yet for Van Persie|
|Lloyd wins Golden Ball, Silver Boot awards|
|Mascherano: I never grabbed Banega|
|Dunga requested Brazil not appeal Neymar´s suspension|
|United States 5 Japan 2: Lloyd stars with hat-trick|
|Fiorentina deny Inter criticism|
|Nani relishing Fenerbahce opportunity|
|Newcastle hold talks over Northampton youngster|
|Cuadrado´s agent plays down Chelsea exit rumours|
|Liverpool´s Alberto set for Deportivo loan|
|Leverkusen suffer surprise defeat, Stuttgart hit six|
|Inter ´dismayed´ at Fiorentina vice-president´s Salah Twitter outburst|
|Blaszczykowski ruled out of Dortmund´s Asia tour|
|Gerrard gets the beers in for LA Galaxy fans|
|De Gea coy over Real links|
|Former Brazil star Carlos handed Delhi reins|
|Ciftci will not push through Celtic switch – agent|
|In-demand Mitrovic considering Roma offer|
|Lehmann calls on Cech to ´get over´ Chelsea|
|Marlos double sinks Monaco|
|Mauritius 0 South Africa 2 (agg 0-5): Bafana set up Angola qualifier|
|Keane relishing Gerrard arrival|
|Palace confirm Cabaye interest|
|Hamburg bring in Spahic after head-butt ban|
|Blatter hits out at France and Germany over World Cup votes|
|Sanchez: World Cup exit spurred Chile to Copa glory|
|Jojic makes Cologne switch, Santana move falls through|
|Carrillo keen to get going at Monaco|
|Micronesia thrashed 38-0 as Fiji triumph in Olympic qualifier|
|Schalke stunned by ´machine´ Caicara|
|MLS Review: Keane shines at Gerrard´s Galaxy unveiling|
|Counter-attacking the key for Japan|
|Jimenez happy at Atletico|
|Gerrard predicts ´successful future´ with Galaxy|
|Iniesta can´t see Real selling Ramos|
|Keshi sacked as Nigeria coach|
|Three finals, three defeats for Messi, Mascherano|
|Nani close to Fenerbahce move|
|Sampaoli revels in ´unbelievable joy´|
|Bravo: Copa victory a dream|
|Martino: Argentina should have won|
|Chile 0 Argentina 0 (4-1 on penalties): Hosts end trophy drought|
|Germany 0 England 1 (after extra time): England make World Cup history|