Asbaghi's first game in charge proved to be a forgettable one as Swansea City triumphed 2-0 at Oakwell to inflict a tenth Championship defeat in 11 matches upon the Reds, who are six points adrift of safety.
Barnsley face a crunch trip to the side just above them in Peterborough United on Saturday.
While Asbaghi's maiden outing at the helm produced an undesirable outcome, Williams has stressed that patience needs to be shown regarding the 36-year-old, who had little time to work with his players ahead of the game.
The fact Barnsley were hard to break down for the majority of the game represented one tick in the game, according to Williams, who has confidence that the side will make positive strides at the other end of the pitch in the coming weeks under Asbaghi.
Williams said: "It is hard for him to change things in a few days, but he seems good so far and in the coming weeks, we will be able to see more of an identity with the ball and without the ball and we can work on things more.
"He came in on Friday for a little talk before the Fulham game and told us to believe that we can beat anyone in this league on our day and expresses his confidence in the lads.
"We have very good players, but just need to start believing more as a team and be more confident and be positive going into games.
"We have set the foundations in being hard to beat and need to be more positive going forward as a team and not lose the ball as easy on the counter-attack.
"It is a tough situation. But we have been here before and I am fairly confident we can get out of this mess and truly believe we are good enough to be moving up the table."
On Asbaghi's first night 'at the office', Williams added: "We were in the game for seventy minutes and made it hard for them to play through us and made them play through the sides.
"But after that, the game got expansive and it was not a contest from then on, really.
"But we have to take the positives that we made it hard for them for the first seventy minutes and build on that on Saturday. We need to be confident and it will change soon.
"The gaffer has come in and wants us to be difficult to play against and hard for teams to break down and it was. Swansea had a lot of the ball and didn't seem to hurt us.
"But once the goal went in, we changed shape and went a bit more attacking and started pressing in ones and twos and the shape went a bit open and it was not really a game from then on."