Grant said: "I feel responsible. I never in my life have put responsibility on other people.
"I'm the manager and am responsible for everything.
"When my team loses at Barnsley there will be many negative things said about it - and I will accept it.
"We needed to win this game and we didn't do it. It's as simple as that.
"We have two major competitions left. I am concentrating on them not other things."
Grant cancelled his players' scheduled day off yesterday and hauled them in for a post-match inquest.
Israeli Grant added: "It's very sad because we'd played so well in the last week.
"It's disappointing. This team has shown that they can play good football."