The Magpies trail the Portuguese side 3-1 after the first leg in the Estadio da Luz, as goals from Rodrigo Moreno, Lima and Oscar Cardozo gave Jorge Jesus's side the advantage going into the second leg at St James' Park.
Pardew told the PA: "We just need to get ourselves in a good position. If we can get a goal with 20 minutes to go, we can do it - that's the agenda for me.
"Our fans need to understand on Thursday, in the quarter-final of the Europa League, that if we go gung-ho looking for two quick goals, we are just going to get killed. We have got to be very intelligent and we have got to be patient."
A last minute winner from Papiss Cisse eased Newcastle's Premier League relegation worries at the weekend in their 1-0 win over Fulham.