Germany's Lukas Podolski has jumped to the defence of his under-fire Arsenal team-mate Mesut Ozil ahead of their opening World Cup match against Portugal on Monday.

Ozil has suffered from a drop in form this season and ex-Germany captain Michael Ballack has criticised him by saying he has looked "lost" on occasion since joining Arsenal from Real Madrid. Joachim Loew is set to name Ozil up front on Monday, replacing him in Germany's attacking midfield role with Bayern Munich's Toni Kroos. And Podolski says the German media should get off Ozil's back.

"Mesut has the quality. He is a world-class player and will bring us plenty of joy in the shirt," Podolski said at Germany's World Cup camp. "You shouldn't write him off, just let the boy play football. He is just the way he is." Germany are amongst the favourites to win the World Cup, but Podolski says Spain's shock 5-1 defeat to the Netherlands on Friday served as a warning to other top sides.

"We're concentrating on our group, which isn't straight forward," he said. "Portugal is a tough opponent, just like the others, but we want to draw some attention to ourselves with a good result and show we're in form from the beginning." Germany's chancellor Angela Merkel will be attending Monday's match at Salvador's Arena Fonte Nova and Podolski says the players will raise their game.

"It's a motivation and something special," he said when asked about Merkel's frequent visits to watch the German team. Loew has been putting his team through their paces at 1300 local time (1600 GMT) to prepare for the early kick-off in Salvador. Warm temperatures and high humidity are expected, but Podolski said they should not affect the Germans. "Doesn't matter if it'll be 50, 55 or 70 degrees, it shouldn't play a role," he said. "When I run out I want to win and everything else doesn't matter. We just need to conserve our energy, you can't run up and down for 90 minutes in this sort of weather."