He told Sky Sports: "I think it is extremely painful. I won't talk away from that. It was a bad performance. It was completely the opposite of what the intention was when we came here. We can only apologise to the fans for the performance. I think no matter if both teams wanted to play shirt, they got more out of that and we couldn't get out. When the team went long, we didn't win enough duels. That is exemplified by the 2-0 goal and the 3-0 goal, where a player went through two or three players. Bad performance and we lost. I have seen a lot of character and fight in this team but we didn't win enough duels. We can call that whatever we want but we didn't win enough."
In Tottenham's 1-0 loss to Chelsea earlier this season, Spurs were widely criticised for producing next to nothing in attack. That happened again against Arsenal, but the scoreline was much less flattering. And Frank stressed they need to address this problem right away.
He said: "That [lack of creativity] has been an ongoing theme that we are working hard to improve. It doesn't look good today or against Chelsea. We need to keep working on it. There were a lot of things in this game we need to do better. We are four months into it and they are further in their journey as a team and that was very obvious today. Of course there will be noise. We played against our biggest rivals and we lost badly. But we keep noise out and we focus. I know this tam is very competitive. I know this team is competitive and we showed that against Man City and PSG. Of course it looks bad today and it was not good enough."
Frank also took full responsibility for getting his approach to the game wrong. However, he felt the way his players performed would have meant that any strategy would have come unstuck against Arsenal.
The Dane added: "I tried to play a 5-4-1. I will always take responsibility as my choice in the end to take the system then and we changed it at half-time. My view is that no matter what formation we play today, we don't have enough duels or intensity in the decisive moments, and it is very difficult to win a football match. The goals I want to see more in detail. The whole game I need to watch tonight an it will be a difficult watch. We were not aggressive and stepped forward when we could and they played it round us."
For the Arsenal game, Frank admitted that he tried to replicate the tactics Tottenham deployed so well in their narrow UEFA Super Cup loss to Paris Saint-Germain in August. But as they fell well short of that against the Gunners, this trip to PSG in the Champions League on Wednesday may be quite daunting.
He said: "That's an extremely hard defeat to take. We are all emotional and frustrated and need to look at it with calm heads. I was very confident going into the game that we could be competitive and we weren't, which was disappointing. We tried to do something different that was very successful against PSG. Today it wasn't and I always take responsibility for my decisions and then when it doesn't go the way we want it to go, that's on me."
