LAS VEGAS — One year after the Kansas City Chiefs and Philadelphia Eagles complained about the surface of the Super Bowl LVII field, the NFL has a whole new set of complaints on their hands.

Multiple members of the San Francisco 49ers organization have complained about the surface of the UNLV practice field since arriving in Las Vegas, alleging that the surface was overly soft and improperly prepared by the league in advance of this week. CBS Sports first reported of the 49ers' dissatisfaction.

A team source told Yahoo Sports on Monday that senior level members of the franchise reached out to the league, while players were in contact with the NFL Players Association regarding the conditions. The source said no resolution was reached regarding the complaints, despite the 49ers seeking out potential alternative practice sites. Head coach Kyle Shanahan said during his media session Monday that the team intends to stick with the UNLV practice site, and that the surface is improving day by day.

The Chiefs are considered the “home” team for the Super Bowl, which grants them the use of the Raiders' facilities for their practices.

The 49ers' players and coaching staff first took the field at noon on Monday, but the team source said the concerns have been ongoing since last week, when several staffers first inspected the playing surface and found it problematic. The primary complaint from the franchise was the league allegedly waiting until last week to put down a sod surface over field turf, resulting in a “spongy” level of softness and “sod seams” that could create footing issues over the course of the week.

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NFL commissioner Roger Goodell slapped back at those assessments during his State of the League news conference on Monday afternoon, defending the field as having met the proper thresholds required for practices.

“That work [on the field] was being done every single day,” Goodell said. “We’ve had 23 experts out there. We had the union out there. All of them think it’s a very playable surface. It’s softer than what they practiced on, but that happens. It’s well within all of our testing standards. It is something we think all of our experts — as well as neutral field inspectors — have all said unanimously that it’s a playable field.”

On Monday night, a union source took issue with Goodell’s assertion that the players association had signed off on the field surface. However, the source said the union wouldn’t have a comment prior to the association's news conference later this week.

It’s the second straight Super Bowl using a natural grass field that utilizes a “tray” system, which allows the surface to be rolled outside of a covered stadium where it can be maintained with water and natural sunlight exposure. That system became problematic in last year’s matchup in the Glendale, Arizona, with a surface that was slick for both teams. The Eagles were particularly upset with that surface slippage, which they believed contributed to them going sackless against Patrick Mahomes in a 38-35 loss despite bringing one the of the league’s best pass rushes into the game.