While Pulis accepts that Foster was at fault for conceding Albion's penalty, he also underlined his worth to the first team.
Asked whether Foster had really caught Matthew Lowton in that particular incident, Pulis told the WBA website: "I haven't seen it but Ben should catch that anyway.
"People will talk about Ben but the thing is he has been absolutely fantastic for us all season.
"Let's not forget he's saved us points and won us games. He's also kept a lot of clean sheets too, as has the defence.
"He's had an off night tonight but there'll be nobody at this football club who will criticise Ben.
"He has been brilliant - he's had a poor night tonight but everybody has those days.
"I don't have to speak to him - he knows. There's no problems. We will dust ourselves down and get going again on Thursday after a day off tomorrow."