"Chris played for Hereford on Saturday and kept a clean sheet, so he'll start and Stephen will be on the bench for the cup game."
Regular keeper Adriano Basso has not recovered from a knock picked up on the weekend.
"Adriano felt alright this morning and we took him training but as soon as he ran out on to the pitch he felt the injury.
"So we've recalled Chris Weale from Hereford and it's only right that your senior keeper plays in goal, so Chris will play at Brentford tomorrow."