The Polish forward contributed 55 goals across all competitions, making him the clear favourite to take home the award.
There were concerns that FIFA may have decided not to run the prize after the Ballon d’Or was cancelled earlier this year.
"Firstly, I think it’s good that FIFA are continuing with the vote this year. It wasn’t clear whether it would happen,” Rummenigge told Bundesliga.com.
“I spoke with the FIFA president about it a couple of times, I told him that we have this vote every year and football has been played this year, you can’t forget that.
“The Bundesliga was completed, the major leagues in Europe were all decided, the Champions League was completed, and I told him, if in 10 years it says '2021 he won, 2022 he won' but there’s a gap in 2020, for me that would be a mistake that you could still correct.
“And I’m happy that FIFA have brought it back, I hope that Robert wins, he’s had an amazing year, I think Robert Lewandowski is in the form of his life, despite the fact he’s 32 now, but it’s not a foregone conclusion.
“I would like him to win, I hope he wins, he’ll have earned it, but we’ll have to wait and see if he does win it at the end of the day."
Neuer suffered a dip in form a few years ago but has since made a claim to retake his previously undeniable position as the best goalkeeper in the world.
Rummenigge even suggested that, in his ninth season at the club, the German has overtaken the likes of Oliver Kahn in the all-time rankings.
"Manuel Neuer is 34 now, and he’s just getting better and better. He’s like a red wine that matures each year," he said.
“He anticipates pretty much every shot, wherever it comes from, and makes the save. We’ve seen that in the last couple of weeks in the Bundesliga and in the Champions League.
“He’s the best goalkeeper in the world, I think he’s even the best goalkeeper of all time.
“We’ve always had good goalkeepers in Germany, at Bayern, when you talk about Sepp Meyer or Oliver Kahn, but I think Manuel Neuer has taken goalkeeping to a new level, and we’re really happy that he’s lining up between the sticks for us."