Marin is confident that the Blues' "better players" would expose Bayern's defence at the Allianz Arena.
The 23-year-old playmaker, who will join Chelsea from Werder Bremen at the end of the season, watched Bayern thrashed 5-2 by Borussia Dortmund in last weekend's DFB-Pokal final.
Asked if their defence was weak, he told BBC Sport: "Yes. I watched the German cup final. They made big errors. Chelsea have better players and will do well if they play offensively."
Marin added: "I think [Chelsea] will win at the weekend. Bayern did a very good job against Real Madrid in the Champions League semi-final, but they did not do well in the cup final."
But Marin was also wary of the attacking threat of Bayern. "I think the strongest Bayern player is Franck Ribery because of his dribbling and because he's a goal threat," Marin said.
"There's also Mario Gomez. He's scored a lot of goals in the Champions League and is a constant danger. If Chelsea can stop them then they will do well."
Marin admitted he had not expected Chelsea to finish as low as sixth in the Premier League, which has left them needing to win on Saturday to qualify for next season's Champions League.
"This club has to play in the Champions League," he said. "Everybody is a bit surprised as to why they didn't play as well as they can.
"Towards the end of the campaign, they were better and reaching the Champions League final was a very good thing."