Spurs lost 2-1 in Seoul as Gabriel Vidovic and Leon Goretzka had Bayern 2-0 ahead before Pedro Porro struck.
Postecoglou said: "I thought it was a tough game for us. Fair to say the players are feeling the effects of us working hard for the last 10 days here and we didn't look really sharp, particularly in that first half and we had to work hard but the players, I think for us, what's important is I think we'll get enormous benefit out of the camp we've had here and I think we paid a price a little bit tonight for the work we've done.
"I thought we were better in the second half, they've also played less minutes. I just thought we looked pretty tired today and it's understandable because the players have worked really hard and you're playing against a strong opponent. It's not fair to judge the players on their performances tonight.
"But yeah, I thought second half we were a lot brighter. The guys who came on gave us some energy and Lucas (Bergvall) and Alfie (Devine) and Emerson, I thought came on and gave us some aggression as well.
"Look, it was, it was a better second half, but I think the intensity dropped as well, which allowed us to get into the game."