Albion were beaten 1-0 at Derby County in the second round of the Carabao Cup on Tuesday evening.
Louie Sibley’s first half goal was enough to send the hosts through to the next stage of the competition.
The Baggies return to Sky Bet Championship action with a trip to Huddersfield on Saturday.
Steve Bruce made 10 changes to last weekend's line-up, naming a similar side to the one that beat Sheffield United in the first round.
They started well in Derbyshire and should have taken the lead on the three minute-mark – Reyes Cleary finding Callum Robinson inside the box, but the Irish international seeing his shot well saved. Adam Reach might have done better, too, when sent through via a lovely Kyle Bartley long-pass, however his finish went over.
Instead it was Derby who grabbed the lead through Sibley’s long-range effort, the midfielder curling past Alex Palmer after 15 minutes.
The Baggies spent the remainder of the first period looking for an equaliser. Matty Phillips headed the best opportunity straight at Joe Wildsmith, while Cleary also blazed off-target.
Derby soaked up the pressure well and were then twice denied a second just before the break thanks to Palmer’s saves from Sibley and David McGoldrick, though still took a one-goal advantage into half-time.
The chances continued to come following the interval – Phillips and Reach both hit over, Cleary had a header saved and Robinson was denied by County’s goalkeeper.
Bruce brought on John Swift, Grady Diangana and Karlan Grant as the visitors ramped up their search.
But Derby were still threatening on the counter and Palmer needed to be alert to deny Sibley’s shot.
Six minutes of stoppage time gave Albion some hope – yet Jed Wallace's low effort, saved by Wildsmith, was the closest they came to a leveller.
Albion: Palmer; Ingram (Fellows 45), Bartley, O’Shea, Ashworth (Swift 66); Livermore, Gardner-Hickman; Phillips (Diangana 66), Robinson (Wallace 76), Reach; Cleary (Grant 66).
Substitutes: Button, Ajayi, Furlong, Molumby.