And Ljungberg admits playing Lacazette alongside Pierre-Emerick Aubameyang leaves the Gunners 'vulnerable defensively'.
"Of course you need to have balance in your team," Ljungberg told beIN Sports after the 3-0 defat to City.
"With Lacazette and Auba we tried in the first two games I was here. We looked vulnerable defensively.
"But of course, they are both great players, that's why I wanted them both on the pitch, but we became very vulnerable defensively.
"So we took the route against West Ham where we changed it and played one of them and then had more defensive organisation.
"And we played extremely well against West Ham and won that game very, very clearly.
"Of course when you play against Man City it's a big step up and especially you need your organisation."