The Royal Blues have been based in Qatar during the winter break but conceded four first-half goals against the Bavarians in a friendly match on Tuesday, prompting sporting director Horst Heldt to demand a dressing-room explanation at half-time.
However, the newly-appointed coach has been left encouraged by the "harmony" his players exhibited at the training camp and thus does not believe there is cause for concern.
"The training camp has been good, we worked great together," Keller told reporters. "There is harmony, but now all the focus is on the Bayern result.
"That does not our training camp justice. I'm quite relaxed about it. and I was clear beforehand about our targets in the Bundesliga."
Midfielder Roman Neustadter, on the other hand, took a less positive stance on the result, admitting that him and his colleagues found it hard to sleep at night after such a heavy loss to their Bundesliga rivals.
"We thought about it a lot and could not put this game aside easily," he remarked.
"Many of us slept very little that night after the game [on Tuesday] because we were extremely angered by our performance."Meanwhile, veteran goalkeeper Timo Hildebrand highlighted the importance of Schalke resuming their season with victories in their next two matches against Hannover and Augsburg.
"That must be our last warning shot, we do not have many more opportunities to turn [our season] around," the 33-year-old added.
"These are two very important games for us, for sure. We do not need to talk about it."