Frank concedes they struggled to create chances on the night.
He remarked afterwards, "I think the positive is that we're going here against a very good home team that you need to respect with the results they've done where they're beating Liverpool, United, Newcastle, Villa, drawing with Chelsea and keeping them on that low amount of chances. They had seven shots in total. I think that's a very, very strong defensive performance.
"I think the back four did excellent, the whole team did excellent, especially Micky and Romero did very well with Thiago and Kevin Schade up there. So that's a positive. I think the amount of unforced errors is the biggest negative, I would say.
"And I think that's the bit where you can make too many mistakes on unforced technical errors that then take out eight, nine maybe good half-transitions where you're not getting into good positions. And then when we were up there, lacked the cutting edge on the day."
Meanwhile, Frank shrugged off the boos from the away support at the final whistle.
"Yeah, I think they seemed like they were not too satisfied and it's fair when we don't hit that top performance overall, but I think it's double-sided because I think what we need to understand is the acknowledgement of the defensive side of the game, which we've done excellent today against a team that just scored three against Liverpool, three against Man Utd, so on and so on. But of course the offensive part needs to be better. There's no two ways about that."