Whether or not you’re a fan of football, you know that the Super Bowl is a pretty big deal.

Last year, 120.8 million Americans watched the game at its peak, the average ad spend for this year is $400 million, and host city San Francisco has spend $4.8 million in preparation for the game, according to Wallethub.

And yet, a few major players—tech giants Google, Facebook, Twitter and Apple—are noticeably absent from so-called Super Bowl City, a ticket-only area in San Francisco, according to CNBC.

Apple aapl has provided some technology for the game, but is a silent partner doing no marketing. Google’s only visible participation goog is providing employee shuttle buses for transportation. Twitter twtr and Facebook fb are nowhere to be seen and only Uber is visibly and officially partnering with the game, according to the publication.

Why the lack of participation? As CNBC notes, “the international crowd which has turned Silicon Valley into the nation’s technological growth engine may not have grown up on a diet of Sunday football.”