"It's a ball for the outfield players and the crowd -- not for the goalkeepers," Germany's number one said at a news conference on Monday.
"When it rains it's not going to be very comfortable for us. It gets very slippery. It also moves a lot in the air."
The World Cup ball is known as the Teamgeist and is made by Adidas. Lehmann compared it to the ball from rival manufacturer Nike.
"The Nike ball feels more like an old fashioned leather ball," he said. "The Adidas one is more plastic.
Lehmann had a thoroughly disappointing Champions League final with Arsenal last week, getting sent off early in the first half and then seeing his side lose 2-1.
He was excused Germany's first pre-World Cup training camp in Sardinia, as had always been the plan.
He hooked up with the team for their second camp in Switzerland on Sunday and said he was looking forward to getting back into competition.
"Playing in the quarter-finals, semi-finals and final is fun and it's a great motivation," Lehmann said. "You want to play more games like that with big crowds."
Germany will be training in Switzerland until May 30. They play the opening match of the World Cup against Costa Rica in Munich on June 9.
The hosts have programmed a training match against Servette to be played behind closed doors on Tuesday. They play the Servette junior side on Thursday.
Their official warm-up games come against Luxembourg in Freiburg on May 27, Japan in Leverkusen on May 30 and Colombia in Moenchengladbach on June 2.