Some coaches would consider it unwise to select an untested defender to mark Cristiano Ronaldo, probably Europe's premier forward.

Germany coach Joachim Loew appears, however, to be contemplating exactly such an option when his team begins its European Championship campaign against Portugal and its star player on Saturday.

Loew insisted Thursday he had not yet made up his mind but spent a lot of time praising Lars Bender, a Bayer Leverkusen midfielder who has never played right back in his club career and who has made only six appearances for his country. With Jerome Boateng out of favor, Bender has played the position in training and Loew was sufficiently impressed.

''I've liked a lot what I've seen in training, Lars Bender could do it well,'' Loew said. ''Bender has incredible potential, it gives me a good feeling.

''I said before the tournament that a few players could find themselves playing in different positions.''

Captain Philipp Lahm could have taken the position but Loew has decided to keep him at left back even though he plays on the right for Bayern Munich, which knocked out Ronaldo's Real Madrid in the Champions League semifinals.

''He is one of the top players in the world, he is sensational,'' Lahm said of Ronaldo. ''But we are prepared well, we have enough quality and depth. We must stop him with a team effort. He dribbles at tremendous pace, he can shoot with both feet and he can finish with his head.''

Portugal is coming off a three-match winless run in friendly games, when it managed to score just once. The 0-0 draws against Poland and Macedonia and 3-1 home loss against to Turkey exposed Portugal's lack of a prolific striker and effective midfield playmaker.

''I don't attach much importance to those friendlies, I've watched other games,'' said Loew, who is warning his team to beware of Portugal's strength on the counterattack.

With forwards Helder Postiga and Hugo Almeida falling short of the form needed to make Portugal's midfield talent tell on the scoresheet, wingers Ronaldo and Nani will likely once again carry the burden of putting the ball in the net.

The pair scored 12 goals in the qualifying campaign, almost double the number scored by Postiga and Almeida (7).

Nani has recovered from a bruised right foot and returned to full training Thursday.

Pepe and Bruno Alves are a solid central-defensive partnership, but full backs Joao Pereira and Fabio Coentrao have been found wanting against weaker teams than Germany, and defensive midfielder Miguel Veloso's misunderstandings with the back four have brought some alarming blunders in recent encounters.

''We've studied our opponents closely and we're ready for what will be a very difficult and very important match,'' goalkeeper Eduardo said.

Defensive lapses could be costly against Germany's experienced striker Miroslav Klose, who is celebrating his 34th birthday on Saturday and has scored 63 international goals.

Germany, which beat Portugal at the 2006 World Cup for third place and again at Euro 2008, is looking for a winning start in its bid for a first continental title since 1996.