Bayern Munich's honorary president Franz Beckenbauer believes the club do not have the depth or the firepower in the squad to compete with Barcelona.
Pep Guardiola's Bayern face Barca in the second leg of the UEFA Champions League semi-final on Tuesday having been beaten 3-0 in the first leg at Camp Nou and losing 1-0 to Augsburg on Saturday.
The Bundesliga champions have been ravaged by injuries and recent times and, without the likes of Franck Ribery and Arjen Robben, do not appear to have the creativity to trouble Barca.
And Beckenbauer said: "I think mistakes were made. I did not understand why they sold [Xherdan] Shaqiri [to Inter] and [Pierre] Hojbjerg [on loan to Augsburg].
"They were great substitutes and they were missing [in the second half of the season]. Of course you cannot expect to get as many injuries as we have. And some players were also out for a longer period of time than expected.
"Bayern were lucky that Thiago [Alcantara] and [Javi] Martinez returned. But we still did not have our full firepower, and you need it when you play in the Champions League semi-finals against Barcelona.
"In these games you need full firepower and it is not enough to play with just the players that are available at the moment. They were punished [for their transfers]. I am sure they will think about the future and the necessary steps to avoid this.
"I can imagine Bayern will buy new players. Some players are older than 30 years, how long can they still play? The games are getting more and more intense. That's why you have got to have a big squad.
"But if half of the squad is injured than you have bad luck. So, I can imagine the squad will be changing."
