Las Vegas, we have a problem.

Ahead of the San Francisco 49ers arriving in Sin City to begin preparation for Super Bowl LVIII, the team's staff discovered an issue.

According to CBS Sports' Jonathan Jones, when 49ers logistics staff arrived last week, they were displeased with the NFC champions' designated practice field at UNLV. Field safety has continued to be a hot topic of discussion this season. But San Francisco made it clear this wasn't an issue of fear about player safety, so much as the team's personal preference of having the field's firmness at 70g (units of gravity) versus the 50g that UNLV's field was measured at.

"They feel the grass is too soft for the team to practice on, and the team has considered alternatives," Jones reported.

The 49ers will conduct their first walkthrough Monday after arriving in Las Vegas on Sunday afternoon.

Because the Chiefs are this year's home team — it annually alternates between conferences — they are practicing at the Las Vegas Raiders' practice facility.

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One of the three fixes to this include the 49ers talking to the NFL about sharing the Raiders' practice field when Kansas City isn't there. Jones said San Francisco's other two choices are to use the UNLV field or to bring in a sod of its liking.

The Raiders' field system is similar to that of the Arizona Cardinals, where the Super Bowl was played last season. Players complained of not being able to get their footing, and after the game, George Toma, a former NFL groundskeeper, said that's because the field didn't get enough sunlight in the lead up to the game and was "overwatered."

"We have brought in a brand-new natural grass surface that is currently installed in the field tray outside Allegiant Stadium," NFL executive vice president Peter O'Reilly said during a call last month. "That has been in for a little bit now and is working through all our standard testing procedures that will take place over the time from installation up through the day before and that Saturday right before the game. Those adjustments and a core maintenance program are in place so we have an optimal field on game day."