The Hoops are 5-2 ahead from the first game at Celtic Park and strong favourites to go through to the group stages for the first time in three years.
Hapoel boss Barak Bakhar admitted that his side would need to achieve the impossible to overcome the three-goal deficit.
Brown, 31, who recently quit international football with Scotland to prolong his Celtic career, steered clear of any outlandish comments, saying: "You never know what can happen in football.
"We need to focus on ourselves more than anything and if we do our job properly we will see what happens.
"We are looking forward to it.
"It was a great game at Celtic Park, the first half was exceptional.
"The previous two seasons we may have been happy with 3-2 but went on and scored a couple more.
"We showed we are a great attacking team and we are defending well as a team."
Boss Brendan Rodgers, who took over from Ronny Deila in May, is enjoying the pressure as he looks to take Celtic into the Champions League at the first time of asking.
He said: "It is high-pressure football but it is a healthy pressure.
"This is a wonderful life we are in and I am very fortunate to be in a job that I love and I just happen to be, at this moment in time, at a club I supported all my life.
"I have incredible supporters and group of players who have no ego, they want to work, they want to run, so it is really enjoyable.
"There are always those little feelings before the games start but once the game starts we will stay calm and focused in what we have to do to get through."
Source : PA
Source: PA