Frank was drafted in as Ange Postecoglou’s replacement over the summer after Tottenham ended last season in 17th place.
Spurs have already shown signs of recovery in defence, with seven clean sheets under Frank in the Premier League, having only earned six league shutouts in the entirety of 2024-25 with Postecoglou in charge.
They won 1-0 at Crystal Palace prior to the Brentford trip.
Frank accepts there are still further areas for improvement but insists there are plenty of reasons to be positive.
“It’s not perfect, we want to be a free-flow team,” Frank said.
“A few things I went to reinforce positively is our last two away performances. The foundation we were building was very strong and we were very strong defensively. That is hugely important and we understood how to close down their transitions.
“We are working very hard on the offensive part of the game.
“Football is a game of mistakes. You lose the ball, that happens – but if half of those can be better, it will provide more attacks.”
Frank, who spent seven years in charge of Brentford, was unable to call on several key figures on Thursday as he continues to contend with a lengthy absentee list.
James Maddison, Dominic Solanke and Dejan Kulusevski are among those on the sidelines with injuries, while Xavi Simons is serving a suspension.
“Expectation is good and I also think we are probably in a bit of a transition,” Frank said.
“Not that we don’t want to play a lot better, but the club, the squad, the injuries, all that taken into consideration is part of that.”
Tottenham return to action on Sunday when Sunderland visit north London at 15:00 GMT.