Francis was meeting the public in the city of Morelia during his five-day trip to Mexico when he was pulled.
He kissed the man in a wheelchair on the head before turning to the crowd.
ITV News reports that he appeared to shout: "No seas egoísta. Qué te pasó, no seas egoísta", which translates to "don't be selfish, don't be selfish."
He then took a few steps back and an announcement was made over the tannoy urging the crowd not to clump together.
According to CNN, the announcer said: "We are asking you to be careful. Please contain yourself. Pope Francis wants to greet us, but if we pile up, it will be difficult to do so."
World's most crowded places
Pope Francis shouts at crowd member in Mexico (video)
Hartsfield–Jackson Atlanta International Airport is the world's busiest airport, accommodating a record-breaking 96.1 million passengers per year (that's 22 million more than London Heathrow). The airport is the home base of Delta Air Lines and is set to be renovated, with plans for a new atrium and a "composure area" after security for passengers to recompose themselves.
Santa Cruz del Islote, off the coast of Colombia, is the world's most densely populated island, with 1,247 people squeezes into its .01 square kilometres. The students attend school on the mainland and residents have to use the neighbouring islands' cemeteries and leisure activities. Fresh water is shipped by Colombian Navy ships and there is no electricity on the island. Watch a video of Santa Cruz del Islote from the sky
One of the busiest motorways in the world is Canada's King's Highway 401, or Macdonald-Cartier Freeway, with the part that passes through Toronto the busiest highway in the world and one of the widest. The highway extends across Southwestern, Central and Eastern Ontario, and has over 500,000 vehicles travelling between Weston Road and Highway 400 in Toronto on some days.
Used by an average of 3.64 million people per day, Tokyo's Shinjuku Station is the world's busiest transport hub. The railway station is served by around a dozen railway and subway lines, including the JR Yamanote Line. It has 36 platforms, including an underground arcade, above ground arcade, numerous hallways and over 200 exits.
You might struggle to find a spot to place your towel at China's Qingdao Number One Bathing Beach, as the sandy stretch in Shandong province attracts hordes of sunbathers due to its downtown location. At its peak time, the beach sees 200,000 tourists each day and boasts soft sand, clear water and mountain views.
It's the second smallest country in the world after Vatican City and Monaco is also the most densely populated country on Earth, with an area of 2.02 square kilometres and a population of about 36,371. Monte Carlo is the most crowded quarter with 15,000 residents.
Famous for its X-crossing, Shibuya Crossing is one of the world's busiest pedestrian crossings, home to the world's most crowded Starbucks which overlooks it and located in front of Shibuya Station, the fourth busiest rail station in Japan. During rush hour, as many as 2,500 people cross the street at the same time from five directions. The spectacle repeats ever two minutes throughout the day, with the crowds only thinning out after midnight when the station closes.
Previously New York's Times Square for attracting 39,200,000 visitors per year, the world's current most visited tourist attraction is the Las Vegas Strip, hosting a whopping 39,668,221 annual visitors. Around 4.2 miles in length, the Strip is famous for its concentration of resort hotels and casinos, home to 15 of the world's 25 largest hotels by room count with a total of over 62,000 rooms.
Renganathan Street is one of the world's most crowded streets, jam-packed with shops and food vendors. The street in Chennai attracts the biggest crowds during festival seasons and finding a parking space is a stressful experience. The narrow strip is just a quarter of a mile long and hosts more than a million people each day.
This double-decked suspension bridge spans the Hudson River, connecting Washington Heights, Manhattan to Fort Lee, New Jersey. The George Washington Bridge carries over 106 million vehicles per year, making it the world's busiest motor vehicle bridge. It's the world's only 14-lane suspension bridge and is home to the world's largest free-flying flag.
As the world's most densely populated city, Manila has over 43,079 people per square kilometre and the capital of the Philippines' most dense area is District 6 with 68,266 inhabitants per square kilometre. The city's population density overtakes that of Kolkata (27,774 inhabitants per km2), Mumbai (22,937 inhabitants per km2) and Paris (20,164 inhabitants per km2).