Williams says the Power won't be throwing in the towel just yet, even though the weekend's result leaves them one game out of the top eight with Hawthorn.
"It makes it more difficult but there are seven games to go, and five of them are at home," he said, after the game.
"It's really emotionally draining, today, as you can imagine. I'm not my zippy self, but there's no doubt we can still make the eight.
"We're going to put every effort into it with the prospect of a big eye on the future."
Williams said his players were disappointed in the way they played against Melbourne, which was reflected in the way captain Dominic Cassisi called them together after the post-match coach's address for a second meeting.
"They're certainly hurting," he said.
"We're all in this together, so we can prepare but the players have to deliver. That's how it goes.
"They understand there's a role to be played and when it comes to game day, the effort and intensity has to come from the players."
Williams was at a loss to explain how that intensity deserted them in the space of a week, after the way they performed against the Brisbane Lions last Saturday.
"Footy is a marvellous thing. It can take you to the greatest highs and the deepest lows," he said.
"Our clearances, too many times we fumbled the ball, or we had it ripped out of our hands. All of those things are related to intensity.
"If you look at their forwards, [Ricky] Petterd and [Liam] Jurrah, they kicked four each.
"Losing [Troy] Chaplin was pretty important for us from last week. You look for differences, and that was a major difference as he was probably our best player last week."
Overall, Williams said the Power simply executed too many ineffective kicks and floundered when it came to the tough stuff on Sunday.
"Credit to Melbourne; they beat us at most of the contested stuff today. We were pretty ordinary, which was really disappointing for us," he said.
"We certainly didn't come into the game underestimating them. We prepared for them to be at their absolute best, and I actually thought we were a bit flattered by half-time.
"Clearances we got smashed at, and that's a very poor result for us. In the last quarter, we dominated clearances and we had enough chances to win the game in the end if we were good enough but we weren't on the day.
"We had four or five players who were particularly poor, which is really disappointing, and our supporters will be very embarrassed by that result for us and it's justified."
He also rued the Power's inability to record consecutive wins, which they haven't done since rounds three and four.
"It's really frustrating for everyone. Consistency is vital for a top side," he said.
"We're still looking for that."
