With the Bundesliga title secured, the 67-year-old picked a second-string team in order to keep his team fresh ahead of next Tuesday's Champions League semi-final first leg against Barcelona.
It did not make a difference to the outcome, as the Bavarian side routed their opponents 4-0 at the Allianz Arena.
"If I said that I had expected it to be like this, then I would be exaggerating," Sky Sports News quotes Heynckes as saying. "But this just reflects what life is like within this team.
"This is Bayern Munich. Everybody wants to perform, wants to do his bit for the success of the team."
Speaking of his decision to rest a number of his first-team stars, Heynckes said: "Of course, my team will look different on Tuesday, that's also why I rested so many today. We have played so many games, and we have so many still to come.
"Therefore, it's important that the players get time to recover and build up their strength again for Tuesday."
The first leg against Barcelona takes place at the Allianz Arena in Munich.