New York CNN  — 

At this point, if you haven’t shipped your Christmas gifts, it may be too late to ensure online purchases will arrive before December 25.

That means a lot of people will be shopping in person this weekend, and the inevitable rush to brick-and-mortar stores is likely to be an even bigger headache for retailers this year as they try to maintain social distancing requirements.

The National Retail Federation, which tracks industry sales trends, estimates more than 150 million Americans plan to shop this Saturday alone, despite the pandemic – and it’s even a slight increase from the roughly 148 million shoppers on the same day last year.

“People are continuing to shop online, but they’re certainly coming up against potential deadlines,” said Katherine Cullen, the NRF’s senior director for industry and consumer insights. “Retailers have been preparing for this for a long time.”

Walmart, Target and Best Buy have said they’ll continue to enforce social distancing and capacity limits already in place.

The retailers are encouraging customers to take advantage of curbside pickup services. Target (CBDY) has already seen a 217% year-over-year increase in same-day fulfillment services, which includes in-store and curbside pick-ups plus items delivered via Target (CBDY)’s Shipt service.

People line up outside GameStop in Herald Square as the city continues the re-opening efforts following restrictions imposed to slow the spread of coronavirus on December 12, 2020 in New York City.

Walmart says it will maintain the 20% store capacity limit it set on April 4, and its mask mandate remains in place for employees and customers. If needed, the company plans to add security on a “store-by-store basis.”

“Generally, we have seen customers have adopted new behaviors and are taking their personal responsibility seriously to help prevent the spread of the virus by wearing masks, practicing social distancing, etc.,” a Walmart spokesman said. “We haven’t seen many instances where stores have reached that [20%] capacity threshold, but if we were to hit that limit in a given store it would be a scenario of one customer in as one customer comes out.”

The last-minute surge could be a boon for small business owners, who have struggled to compete with e-commerce giants like Amazon this year even more than in the past, according to the National Small Business Association, which represents 65,000 independent businesses nationwide.

Logan Boone, co-owner of Boone Mountain Sports in Evergreen, Colorado, told CNN Business his family’s business has been limiting in-store traffic throughout the holiday season, and they have introduced in-store pickup services on the website to better compete with online retailers.

He’s expecting and looking forward to larger crowds this weekend: “We’re just going to bring people in as much as possible and make sure they’re all happy and healthy and safe.”