Alan Pardew, whose job was under serious threat, managed to turn the club's fortunes around and Newcastle now find themselves comfortably mid-table going into December, a turnaround that Janmaat always thought was possible.
"I never really had any doubts," the Netherlands international told the Shields Gazette. "Of course, at the start of the season, things were not good, and there was a lot of pressure on the trainer and on us as players.
"That was not nice, but I always had the belief that we had a good enough squad to do much better. I probably didn't expect us to win six games in a row, but I always knew we were capable of going on a much better run and turning things around.
"We have shown in this run that we can win different types of matches. We can attack teams and cause problems on the break, but we can also be organised and hard to break down when we have to be. That is a big strength of the team."
Newcastle play host to unbeaten Chelsea in the Premier League's early kickoff this afternoon.