Middlesbrough boss Gareth Southgate is angry with the manner of Arsenal's opening goal in yesterday's 2-0 defeat at Emirates stadium.
Arsenal's Nicklas Bendtner was offside and in front of keeper Brad Jones as Cesc Fabregas put the Gunners ahead.
Southgate said: "There's no question it's offside and no question, in our opinion, it's interfering with play. It knocked the wind out of our sails.
"But we've got to look at the 90 minutes and we didn't do enough to get a result. I thought we did OK but OK isn't enough when you come to somewhere like this, you've got to be outstanding because they are a top-quality team.
"We kept our discipline well - but if you get a half-chance you've got to take it.
"We had a decent chance in the second half and some reasonable breaks in the first. But it was always going to be difficult. There's 30 odd-points between the two teams, it's obviously a huge gulf.
"But I can't fault the players' commitment, there was no disgrace in how we performed."