Leeds United lost 2-1 to Gary Rowett's side at Elland Road yesterday.
Monk's side went into the game owing the Elland Road faithful a good performance after losing 3-0 at QPR in their Championship opener seven days ago.
And Leeds fans would have been pleased with the team's first-half display after the Whites showed a bit of bottle when Hadi Sacko - on a season-long loan from Sporting Lisbon - cancelled out Jacques Maghoma's opener.
But Michael Morrison re-established a lead for Birmingham on 55 minutes and United had no response this time, consigning themselves to back-to-back Championship defeats to sit six points adrift of the pace already.
The Leeds boss was measured and calm with his post-match comments at Loftus Road last week, but the 38-year-old was in no mood to sugar coat this defeat, highlighting a perceived "softness" on a number of occasions.
"There's been a bit of softness here down the years, and I saw that softness today which I didn't like," he said to TV Yorkshire. "I made it very clear to the players afterwards that it's not acceptable - that softness. Whenever you're on the pitch you have to be a man and put your body on the line. You have to suffer physically and we didn't."
Monk certainly has no intention of mollycoddling his troops, but there is a line to be drawn between shielding his players and throwing them under the bus.
Of course, he did not hang them out to dry on this occasion as much as he probably could have, but overt criticism is not conducive for long-term success.