Goals from former Saddlers Amadou Bakayoko and Jordy Hiwula, coupled with Bright Enobakhare's second-half penalty, saw the Saddlers slip to their fifth league defeat on the bounce, leaving them just two points above the relegation zone.
Keates, who has been under increasing pressure over recent weeks, admitted that his team's performance was simply not good enough before going on to praise goalkeeper Liam Roberts for being the only player able to leave the pitch with his head held high.