The New Zealand-born out-half has played 80 minutes in all of Leinster's GUINNESS PRO12 games this season aside from against Zebre where Madigan led his team to a 20-3 victory with a stellar performance.
Head coach Matt O'Connor's selection headache may be increased by Sexton's homecoming from Racing Metro for the 2015/16 campaign but Gopperth remains focused on this year's task, starting with a visit to Castres this weekend.
And the 31-year-old believes Madigan's versatility that allows both players to line up in the backline can help inspire Leinster's attacking talents after a mixed start to the season.
"Johnny's return isn't something that you can get distracted by," Gopperth told the Irish Independent.
"Ian and I are still the number one and two out-halves. Or two and one, whichever way it's selected on any given week - that is Matt's decision.
"Johnny is a Racing player and he has plenty of rugby himself to focus on. Ian and I are just focused on getting the best out of each other for the benefit of the team.
"It's a two-way thing - it keeps the opposition guessing first. If there is a ruck in the middle, you can split your receivers either side. It opens a lot more space up.
"Then if you see a half-gap, you know you can go for it as there is someone else behind you on their feet who can direct the play in your absence. Two players that can direct play and kick can only be a good thing."
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