Jol saw his team come from behind against Everton to win their first game since the opening day of the season on Tuesday night, and expects Cardiff to be difficult to break down when the Premier League returns at the weekend.
"If you look at Cardiff, they've not conceded many goals," he told reporters. "There are a lot of teams who have conceded more goals than them. I wouldn't say they look defensive but they look very organised, especially if you saw their home game against Manchester City.
"They look very organised, they've got pace up front and they've always got this mentality that they would like to hurt you. So it's not a walkover, of course, it's a strong team with good qualities.
"They invested a few bob as well so it won't be easy but how many games are easy in the league? Hopefully we're strong enough."
The game kicks off at 3pm on Saturday.