Max sometimes wears a white glove, or a black glove on his left hand, depending on the scene. In the comics, this is because Max is actually two Agents, who are twins. However, in the film, it's because of a nasty scar on his hand.
Director Sylvain White was attracted by the realistic nature of the comic, to do the film: "What appealed to me about The Losers, was that it wasn't the typical superhero-with-superpowers thing. It was based on real characters, realistic characters - and based in reality, like a lot of the European graphic novels that I had grown up reading."
When Jensen unlocks Max's hard drive, the code that comes up on-screen, is actually the source code of the web page for ordering a trial version of MathCore, a program for compiling mathematical functions.
Chris Evans, Zoe Saldana, and Idris Elba went on to star in the Marvel Cinematic Universe. Evans in the Captain America and Avengers franchises. Saldana in the Guardians of the Galaxy franchise, and Elba played the role of Heimdall in the Thor franchise.
Production Designer Aaron Osborne and Cinematographer Scott Kevan attempted to enhance the color scheme of the comics, where only two to three colors were used to convey the tone of each setting, so they charted the whole movie with certain color schemes for each location, and different shades as time passed("Every chapter of the comic books is a new environment distinguished by different color palettes - so every time we are in a new city or country, the aesthetic of the film changes completely, so there is no homogeneous look. It's very eclectic.").
The uniforms, that the security company at the end of the film wears, are the Navy Working Uniform made from digital camouflage. The color and pattern was designed specifically for the U.S. Navy. This is the first movie to be shown with this uniform worn by anyone.
Jeffrey Dean Morgan (Clay), Zoe Saldana (Aisha), Chris Evans (Jensen) and Idris Elba (Roque), have all starred in other comic book properties. Morgan (Comedian, Thomas Wayne, and Negan) Watchmen, Batman V. Superman: Dawn of Justice, and The Walking Dead. Saldana (Gamora) in Guardians of the Galaxy 1 & 2. Elba (Heimdall, Moreau) in Thor 1 & 2, and Ghost Rider 2. Evans (The Human Torch, Curtis, Casey Jones, and Captain America) in Fantastic Four 1 & 2, Snowpiercer, TMNT (2007), and Captain America: The First Avenger, Avengers 1 & 2, Civil War, and Spiderman: Homecoming.
Jensen tries to bluff his way past security guards, by claiming he's part of a secret government experiment. Chris Evans would later appear in the Marvel Cinematic Universe to portray Steve Rogers, who became Captain America, as part of a secret government experiment.
Originally Tim Story was to direct, citing influences from the war drama Black Hawk Down (2001) and the television miniseries Band of Brothers (2001): "I was looking for a film that would have edge, but I wanted to keep the tongue-and-cheek, where the characters have a little fun with each other." He was later replaced with Sylvain White.
When Jensen enters through the warehouse roof at the Port of Los Angeles, to let Clay and Roque in the door, he says "Disco" as he touches down on the ground to signify that he's arrived. Chris Evans previously played Detective Paul Diskant, in the movie Street Kings (2008), and his nickname was Disco, although he didn't particularly like the nickname.
The aircraft used in the film are anachronistic. The fighter which attacks the compound and destroys the rescue helicopter is a Mikoyan-Gurevich MiG-21 (NATO reporting name "Fishbed"). The helicopters are Eurocopter AS332 Super Pumas. Neither of these types of aircraft are operated by US military or even by US special forces. The Super Pumas were originally built by French manufacturers Aérospatiale and were supplied to some countries in Central and South America. It would make sense for the filmmakers to source local aircraft for the film, which was shot in Puerto Rico, but nobody in the Americas or the Caribbean except Cuba has ever operated the MiG-21, which means the footage of it was probably archival and/or computer-generated for the film.
In the scene where The Losers "chopperjack" the military helicopter, Coogar is seen wearing a Che Guevara t-shirt. Óscar Jaenada starred in Che: Part Two, Guerrilla, in 2008. His character was called Dario.
When Roque enters the store through the ceiling after Jensen is shot, he drops down near a long display of dolls called "Girls Of America". They're the same dolls Jensen and Cougar were assembling in the Bolivian factory.