The retired Germany midfielder questions the mental strength of the players at his former club, concerned that the team might have a complex after their recent final defeats
Die Roten face Bundesliga rivals Borussia Dortmund at Wembley on May 25 after losing against Inter in 2010 and falling to defeat to Chelsea on penalties last season at the same stage in their home ground.
Hamann revealed that he was worried that recent experience of being runners-up might weigh heavy on the minds of the team.
"In the past three years Bayern have lost two Champions League finals against Inter and Chelsea," the 39-year-old German is quoted as saying by tz-online.de.
"Those two sides were were nowhere near as good as Dortmund are now. Therefore, I wonder how deep the scars will be."
Hamann, a Champions League winner with Liverpool in 2005, is convinced that the Bavarians will struggle to ignore their previous failures and might once again falter as a result.
"If as a tennis player you have won at Wimbledon, you know next year what you need to do," he continued.
"Bayern know that they've played for the title twice. You have doubts. Now they've got an excellent team, and the pressure is on to finally deliver."