Bayern Munich will struggle to overcome their first-leg deficit to Atletico Madrid in the Champions League semi-final, according to former midfielder Michael Ballack.
A stunning solo goal from Saul Niguez was enough to give Diego Simeone's side the advantage heading into Tuesday's return fixture at the Allianz Arena.
Pep Guardiola has guided Bayern to three consecutive Champions League semi-finals but suffered defeat in the previous two campaigns to eventual winners Real Madrid and Barcelona.
And Ballack, who was a beaten finalist for Bayer Leverkusen and Chelsea during his playing career, has cast doubt on Bayern's chances of progression this time.
"It's difficult," he told Omnisport. "One-nil is not a great result, not scoring away. They're strong enough to beat every team at home but this Atletico team seems very strong, they've grown in terms of experience as well since the defeat to Real Madrid two years ago.
"It will be really difficult for Bayern to reach the final."
Guardiola will leave Bayern at the end of the season to take charge at Manchester City, and Ballack believes he should be praised for his impact on German football regardless of whether they finish the campaign as European champions.
"He's still a great coach, he brought so much to the Bundesliga, to German football," he said. "It was a big achievement for German football as well, to get him.
"He hasn't won the Champions League so far but that's really difficult for a club to win it every two or three years. History shows that. He picked a team after they won the Champions League, which is not easy.
"But he's looking for a new challenge now in England and I wish him all the best."