The list names Kyle Shanahan, Zac Taylor, Dan Campbell, Todd Bowles, Shane Steichen and Aaron Glenn as facing pressure before training camp.
Reasons range from repeated playoff shortcomings and missed post-season berths to poor records, with Glenn under scrutiny after the Jets went 3-14 in his first year.
The ranking follows a turbulent previous season in which long-serving coaches Mike Tomlin, John Harbaugh, Sean McDermott and Kevin Stefanski were all dismissed.
After trading stars for Mike Evans, can Shanahan's high-stakes roster finally deliver a championship to San Francisco?
Is Kyle Shanahan the next Andy Reid, a great coach who needs a new team to finally win a Super Bowl?