General overall view of New England Patriots and Atlanta Falcons helmets and NFL Wilson official Duke Super Bowl LI logo football at NRG Stadium. (Kirby Lee-USA TODAY Sports)

As football spectators, professional players and fans at home are getting their final preparations in order for the Super Bowl LI, authorities are working under the radar on high-security measures in Houston.

“On the day of the big game, we will be here, but our presence may not necessarily be seen. We will have multiple elements in place onsite as well as offsite,” FBI assistant special agent-in-charge Mark Webster said in an FBI news release.

Webster is in charge of organizing security measures for the bureau during the Super Bowl. He said that officials are using “all the elements within [the] office” to heighten security efforts because the championship is a national event. These resources include surveillance specialists, cybersquads, intelligence analysts and SWAT teams, who were deployed as many as 10 days prior to the game to keep celebrations around the area in check.

Terrorist attacks around the world in recent years have put authorities on high alert although officials have cited no authentic threats against this year’s Super Bowl. Regardless, of the level of attention the national event receives, with more than 73,000 fans planning to fill the NRG Stadium — formerly Reliant Stadium — extra measures are expected: "We have almost three miles of security perimeter around our venues," NFL’s vice president of security Cathy Lanier told a news conference.

With greater security measures come more expenses and costs are estimated at around $5.5 million to keep the area safe. The Houston Super Bowl Committee is expected to reimburse Houston for these expenditures, the Houston Press reported.

Lady Gaga spoke to the media during the Super Bowl LI halftime show press conference at Media Center. (Matthew Emmons/USA TODAY Sports)