Despite being one goal down from the first leg held here on April 1, Jelius wants his players to try their best to turn the tie.
"Our priority is of course to keep the team in the Premier League next season but since we are still in the Cup competition, we should not just throw away the game cheaply.
"I want the players to maintain the mental strength as they did during the 1-0 win against Kuantan FA in our last league match. It is important that the players can keep the winning momentum.
"To me, Negeri Sembilan are a well prepared team this season. They have been winning matches since the start of the season and we realised their strength.
"We have 90 minutes to show what we can do. As they say, 'the ball is round', so we will give our best and see what happens even though we are the underdog in the tie tomorrow."
The coach also said there will only be one change from the starting line-up against Kuantan FA.
"I don't think there will be any changes apart from left back Jenius Karib who is nursing a groin discomfort.
It is not a major problem and even with his absence because we have many players available in that position but I will most probably put Dendy Lowa ahead of the others as he did a very good job before his suspension to miss the Kuantan FA match."
The only concern for him is in the strikers position as import Jonathan Behe is out of contention together with midfielder Sofiane Choubani.
'We are lacking strikers at the moment, we only have Rahman Shah (Marajeh), Leopold (Alfonso) and Maxsius (Musa) who can play up front.
"Now with Jonathan out of the picture, we are hoping Hamran Peter from the President Cup squad will stay back and rejoin us after the away league match against Kuala Lumpur today (Thursday)," he said. - GL Oh