The former Everton left-back had to go off after taking a knock to his ankle during the first half of Saturday's 1-1 draw at Gillingham in League One.
Boss Uwe Rosler revealed afterwards that Bidwell would undergo a scan to determine the extent of the damage.
Walsall, like the Bees, are unbeaten this season and Rosler is predicting an exciting match.
He said: "Walsall have a counter-attacking team.
"They are dangerous, with a fluid front four and two sitting players.
"We have to play at our tempo in our way. It should be an entertaining game."