The 23-year-old Alvarez, who helped Argentina win the World Cup, has scored 10 goals in 33 appearances during his first season in Manchester.
Palmeiras reached their first Copa Libertadores final since 2000 after edging River Plate despite a thrilling second-leg loss on Tuesday.
River Plate were minutes from defending the Copa Libertadores until Gabriel Barbosa snatched victory for Flamengo
Gabriel Barbosa scored the all-important goal for Flamengo at the Metropolitano Stadium in Ecuador to bag Copa Libertadores 2022.
River Plate will play their next two Copa Libertadores home games behind closed doors but keep the 2018 title after Boca Juniors' appeal
The second leg of the final will be played at River's Monumental stadium on November 24. The match is expected to be attended by Russian President Vladimir Putin, who will be in the South American country for the 2018 G20...
River Plate have seen 20 players, including all of their eligible goalkeepers, test positive for COVID-19, leaving Marcelo Gallardo with just 10 fit members of his squad
It's the most explosive and combustible match in which fans have been banned from travelling to away matches since 2013 due to football-related violence that has seen 305 supporters killed in the last 50 years.