"The NFL said that this field met minimum testing standards," said NFL Players Association President JC Tretter. "We clearly need to re-evaluate what is an acceptable surface for players to compete on. We need new testing metrics looking at the performance and safety of every field. The NFL can and should do better."
There was an Elton John concert at Soldier Field on August 5. There are three more concerts scheduled there over the next few weeks, on August 19, August 20 and September 3.
The Bears beat the Chiefs at Soldier Field 19-14. Bears quarterback Justin Fields said things were worse when the Bears practiced at Soldier Field on Tuesday.
"I knew how our grass was," he said. "So I knew other teams didn't know how it was, so I kind of used it to my advantage in running and stuff like that, using the long spikes and stuff like that."
The Associated Press contributed to this report.