In the final mission, "Alejandro.docx," Alejandro becomes a key figure in the chaos caused by the attack on the cartel. The team includes Johnny "Soap" MacTavish, Vaqueiro, who is a cartel deserter, as well as Simon "Ghost" Riley. After fighting their way through the cartel, they discover that they have mistaken Gassan. They are then attacked by elements of the Mexican army and forced to flee to a hideout. Vaqueiro, the only survivor of the team, recounts his past as a child who was pursued by the army, while Rodriguez tries to contact him on the radio. After Rodriguez is killed by a sniper's bullet, Alejandro tells Ghost and Soap that they must jump off the cliff. Together, they jump off the cliff and swim to an evacuation site on a bridge guarded by Philip Graves and an AC-130. After being rescued on the bridge, Alejandro leads the team to a nearby cartel base where Gassan was spotted.

During the air support mission, Alejandro helps Ghost and Soap destroy several buildings on the cartel's territory while Rudy captures Gassan from above. This capture leads to Rudy taking Gassan hostage, which results in his departure from Shadow Company. When they arrive on the roof, Alejandro takes a hostage. The rest of the team on the roof in the city of Olimias is attacked by cartel fighters and Mexican army soldiers trying to free Gassan. Ghost and Soap provide them with air cover. Later, Alejandro is present at Gassan's interrogation in the Mexican desert.

In "Black Water," Alejandro, Graves, Soap, and Ghost conduct an attack on an abandoned oil platform in the Gulf of Mexico used by the cartel as a transfer point. During the attack, rockets hit the platform, and Alejandro remains on the platform while Ghost, Soap, and Graves attack a nearby cargo ship to prevent the launch of a rocket towards New Orleans. Ghost and Soap quickly evacuate the platform before it explodes. Upon returning to the base, Alejandro discovers that his orders have been intercepted by Shadow Company, and the Vaqueiros on the base have been captured.

During the escape, Alejandro and the rest of the Vaqueiros are freed by Rudy, Ghost, and Soap. They fight the remaining Shadow fighters, and at the end, they are helped by newcomer John Price and Kyle "Gambit" Garrick. After escaping, they return to their hideout. Alejandro is once again allied with Rudy, and together with members of TF-141, they pursue Valeria through underground tunnels. They successfully capture Valeria, and Alejandro orders the killing of Graves for his betrayal. The team successfully completes their objective.

Later, Alejandro and Rudy show Valeria in custody as they bid farewell to Soap, Ghost, and Price at the base.