The sides meet in Lancashire in their quarter-final replay after the initial tie ended goalless at Anfield, with Gary Bowyer's Championship outfit targetting a third Premier League scalp of the season.
While Rovers look set for a mid-table finish in the league, Gestede and King have shone in the FA Cup and former striker Jansen backed the pair to cause Liverpool problems.
Asked whether the duo were likely to be the attacking focal points for Rovers, Jansen told Perform: "You would imagine so, Gestede in particular caused problems at Anfield.
"I watched them against Liverpool and Gestede was a handful for them so I'm sure he'll be a handful at home.
"They did the hard part at Anfield and with Blackburn not having anything to play for at the end of the season, while Liverpool are looking for the Champions League spots, I think it'll mean more to Blackburn on the night.
"I'm sure the crowd will get behind them and it'll be a good one.
"I know what the fans are like down at Ewood and they'll get behind the lads so hopefully they can cause an upset."
Blackburn have beaten Stoke City and Swansea City on their way to the last four.
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
‘He’ll still be playing at 40 at a good level because he’s in such good shape and looks after himself so well. He does everything to be a top professional’: Ex-Liverpool coach insists Mohamed Salah has plenty more miles in the tank
