Liverpool have only won one of their last six matches in all competitions and are bidding to return to winning ways at Newcastle after being held to a 1-1 draw by Spartak Moscow in the Champions League in midweek.
Newcastle were on a three-game winning run in the Premier League before losing 1-0 at Brighton last weekend, but Molby said he did not expect the Magpies to pose a big threat to the Reds.
"Quite simply I don't believe they will not have enough quality to trouble Liverpool," he told the Liverpool Echo.
"There are teams you look at, with certain players and how they play, that you can see that they could cause some problems.
"But Newcastle aren't one of those unless Liverpool very much underperform on the day."
Molby urged Liverpool fans to keep the faith with Klopp and added that the Reds were unlucky to only get a point against Spartak Moscow despite dominating the match.
"Of course Liverpool should have got more against Spartak in Moscow this week," he said. "They played well, created chances and didn't take them.
"Is it a massive problem though? I don't think so.
"For me Liverpool will win their next three Champions League games and go through. It was still slightly disappointing because it was a game which was there for the taking."
Molby added that the current Liverpool squad was good enough to secure a top-four finish in the Premier League this season.
"I trust the team to be competitive and to be close to the top four or in it – that's where we are at the moment," he said.
"There are a couple of top teams who have significantly strengthened in the summer and they could run away from us a little bit."