While the home side have recorded four points from their opening two fixtures, last season's playoff runners-up have posted one win and one defeat.
However, progressing past Southampton and West Bromwich Albion in the EFL Cup, both when fielding weakened teams away from home, suggests that Thomas Frank is continuing to develop this promising group of players.
Their opening-day setback at Birmingham City has now been forgotten and expectation levels will only continue to rise with the shrewd addition of Saman Ghoddos, a player who should be an ideal fit for Brentford's style of play.
Frank will no doubt want to keep everyone's feet on the ground at this stage of the season when the added pressure only hindered their progress back in July.
That said, all eyes are on their evolution as they adopt a unique transfer policy, one which shows no signs of failing any time soon.
Like the visitors, Millwall performed above expectations during the last campaign, only missing out on a place in the playoffs by two points.
Although Rowett was disappointed to see his side's unbeaten start to the season come to an end against Burnley in the EFL Cup, the Lions boss will be happy to focus his attention on league matters.
Improving in the final third will be at the top of his agenda having witnessed his team score just once in games against Stoke City, Rotherham United and the Clarets.
Millwall Championship form: DW
Millwall form (all competitions): WDWWL
Brentford Championship form: LW
Brentford form (all competitions): DLWWW
Tottenham Hotspur loanee Troy Parrott is expected to miss out for Millwall due to an ankle injury.
Having made changes for their EFL Cup tie, Rowett could revert back to the team which began the victory over Rotherham.
Brentford boss Frank will also recall the players who were rested for the midweek clash with West Brom.
Millwall possible starting lineup:
Bialkowski; Hutchinson, Pearce, Cooper; Romeo, Leonard, Woods, Malone; Wallace, Bradshaw, Bennett
Brentford possible starting lineup:
Daniels; Dalsgaard, Jansson, Pinnock, Henry; Dasilva, Norgaard, Marcondes; Mbuemo, Toney, Canos
We say: Millwall 1-2 Brentford
While Millwall have looked strong at the back in their opening two matches, we cannot ignore that Brentford are beginning to click into gear in the final third. Although little may separate the teams come the final whistle, the Bees could prevail by the odd goal in three.