The Bees host the Seagulls on Saturday looking to maintain their impressive unbeaten start before the international break.
Having marked their return to the top flight for the first time since the 1946/47 season with a memorable 2-0 home win over Arsenal on the opening night, Brentford earned away draws at Aston Villa and then Crystal Palace to sit 10th.
However, Brighton, who finished 16th last season, have also enjoyed a decent start with six points from their opening three games, and Frank has warned the visit of Graham Potter’s side will prove the sternest test so far.
“Brighton is a club who have done very well the last years,” said the Dane, who took Brentford up via the Sky Bet Championship play-offs.
“This is the fifth season in the Premier League. I think Graham Potter and his coaching staff have done fantastically good.
“They were unlucky last year not to finish higher high in the league, and I think it’s going to be our toughest opponent so far.
“That is said with the biggest respect to the three previous teams we played for various reasons.
“Arsenal had a disrupted pre-season with Covid and injury with one or two players against us.
“Crystal Palace had just a new manager, a lot of incomings. Villa also had a lot of disrupted pre-season with Covid and a lot of other issues.
“Now we are facing a team that had the same manager going through his third season, no issues, just adding extra layers, so this going to be unbelievable tough challenge.”
Brighton dropped their first points of the new season when they were beaten 2-0 at home by Everton ahead of the international break.
Frank said: “I like the way they play. They are very clear in the way they want to build the game.
“They want to dominate on the ball to find very good positions, they are very difficult to handle in that.
“Then they have one of our former players (Neal) Maupay and I’m looking forward to seeing him.
“I really enjoy watching him play and I’m pleased that he’s doing well in the Premier League for Brighton.”
Despite Brentford’s own positive start, Frank knows the squad remain very much a work in progress.
“It is important, first and foremost, to keep the foundation we laid in our performances,” he said.
“In that, I am talking about special defensive side of the game in terms of various things, pressing forward, pressing high, very aggressive, with big intensity and well structured, I think that is a key thing for us to do.
“We all know we also want try to build from the back and try to be slightly more dominant.
“But we also need to understand that we just stepped the level up. That can be slightly more difficult.
“I think there was signs of spells where we did very well on the ball against Villa, found good positions.
“Then we need to find that moment or add that quality in the final pass or decision making.”
Frank reported no fresh selection problems following the international break, with Mads Bech Sorensen still sidelined by a knee issue and Josh Dasilva continuing his recovery.
Defender Frank Onyeka is back in training following his positive Covid-19 test.Brentford will also hope to have new arrival Mathias Jorgensen – also known as Zanka – available for action soon after announcing the experienced Denmark international’s signing on Thursday.
The 31-year-old defender has joined the Bees on a one-year contract, subject to confirmation of a work permit and international clearance, having been a free agent after leaving Fenerbahce this summer.
Frank said of the former Huddersfield centre-back: “Zanka brings a wealth of experience from different leagues and a lot of international games, he has also played in the Premier League before. That experience and leadership is especially important, and it is great to get him in.”