[5][6] River Plate toured the United States for pre-season, with the first match being played on 27 June against Ventura County Fusion at the Wallis Annenberg Stadium in Los Angeles as they ran out 5–0 winners; with Lucas Beltrán netting twice.
[13] River met Ventura County Fushion of USL League Two for a secondary match-up on 4 July, with Jorge Carrascal scoring four times in a 7–0 victory.
[16][17] On matchday two of the Colossus Cup, River beat another Mexican team in América with goals from Julián Álvarez and Cristian Ferreira.
[20][21] On 23 July, River Plate met Brazilian club Cruzeiro in the first leg of a Copa Libertadores round of sixteen encounter, as the two played out a goalless draw at Estadio Monumental.
[27][28] River built upon their point on the opening day in the Primera División over Argentinos Juniors with a 3–0 win versus Lanús on 4 August on home soil.
[32] 10 August saw Santiago Vera leave River Plate, as the midfielder agreed terms on a move to Paraguayan Primera División outfit Olimpia.
[36] River Plate defeated Cerro Porteño in the first leg of a Copa Libertadores quarter-final on 22 August, winning 2–0 after Ignacio Fernández and Rafael Santos Borré netted spot-kicks.
[37] River's first league loss came three days later, as Talleres won at the Estadio Monumental Antonio Vespucio Liberti for the first time in twenty-nine years.
[38] On 29 August, River progressed to the Copa Libertadores semi-finals after beating Paraguayan side Cerro Porteño 3–1 on aggregate, having drawn 1–1 in the second leg in Asunción.
On the first day of October, River beat rivals Boca in a tense first leg of the Libertadores semi-finals 2–0 with goals from Borre and Fernandez.
In June 2019, River Plate were announced as one of four clubs, alongside Guadalajara, América and Boca Juniors, that would take part in the inaugural Colossus Cup in the United States.
[97] They were scheduled to face the Liga MX duo at SDCCU Stadium in San Diego on 28 June and at CenturyLink Field in Seattle on 6 July.
[101] Win Draw Loss River Plate began their cup run against Primera B Nacional side Gimnasia y Esgrima (M) on 16 July 2019, at the Estadio Único in Villa Mercedes.