49ers displeased with Super Bowl practice field, sources say | ESPN
The NFL put in a sod field on top of field turf and started laying it just last week when the NFL ordinarily requires Super Bowl practice fields to meet certain standards in December, sources told Schefter.
The NFL hardness score for fields averages 78, with no field being less than 70. The 49ers field is considered in the 50s, sources told Schefter.
The 49ers will hold their first walk-through practice on the field later Monday.