While the Baggies disposed of League Two newcomers Harrogate Town last week, the Bees recorded an impressive 2-0 win away at Southampton.
For much of the first half against Everton on Saturday, West Brom suggested that they had shaken off the disappointment of succumbing tamely to Leicester City on the opening weekend of the season.
Nevertheless, the West Midlands outfit can focus their attention on facing Brentford in the short term as Bilic looks to give some much-needed minutes to his second string.
Although they never performed to their best against Harrogate, much of that was down to two spectacular strikes in the first half leaving West Brom in control for the remainder of the contest.
Bilic will want to see more from his side, however, and it will be required against opponents who have clicked into gear over the past seven days.
Since their surprise defeat at Birmingham City in the Championship, five goals and two clean sheets have come in matches against Southampton and Huddersfield Town respectively.
Despite being focused on earning promotion to the Premier League, Frank will want to see how the backup members of his squad handle the step up against stronger opposition as he contemplates potential additions before the end of the summer transfer window.
Frank may opt to rest Ivan Toney for this contest, although it would represent another opportunity for the big-money addition to break his three-game duck for his new side.
West Bromwich Albion EFL Cup form: W
West Bromwich Albion form (all competitions): LWL
Brentford EFL Cup form: DW
Brentford form (all competitions): DLWW
With Gibbs serving a suspension, Conor Townsend will feature on the left-hand side of defence, whether that be in a back four or five.
Despite speculation regarding his future, goalkeeper David Raya could return to the starting lineup for the first time this season.
West Bromwich Albion possible starting lineup:
Button; Peltier, Ivanovic, Kipre, Townsend; Field, Harper; Phillips; Gallagher, Edwards; Robson-Kanu
Brentford possible starting lineup:
Raya; Rasmussen, Goode, Sorensen, Thompson; Dasilva, Zamburek, Baptiste; Fosu-Henry, Forss, Canos
We say: West Bromwich Albion 1-2 Brentford
Although both managers will rotate their squad, a closely-fought encounter should still occur at The Hawthorns. However, we feel that the Bees can only build on defeating the Saints, showing the greater threat in attack against a backline devoid of confidence.