Portugal and Chile go into the Confederations Cup with full-strength squads and ambitions to win another major title after continental glory.
The European and South American champions are the favourites to reach the final on July 2 in St Petersburg given that world champions Germany are in Russia with many untested players.
Hosts Russia are meanwhile hoping a new generation will show they can compete under tournament pressure ahead of the World Cup next year on home soil.
Russia kick off the eight nation tournament, described by world governing body FIFA as the “festival of champions”, against New Zealand in St Petersburg on Saturday.
It is the 10th edition of the competition at which the six continental federation champions are joined by the hosts and the World Cup holders.
Russia and New Zealand are in Group A with Portugal and Mexico, who meet on Sunday in Kazan, while Group B features Cameroon, Chile, Germany and Australia.
Group B action begins Sunday when Cameroon play Chile in Moscow, while Germany meet Australia in Sochi on Monday.
The tournament is a dress rehearsal for Russia ahead of the World Cup but also a key event for FIFA, which will also be taking the opportunity of continuing trials with video assistance technology for referees.
However, with World Cup expansion plans and the 2022 Qatar World Cup moved to start in November because of the summer heat, the Confed Cup’s future is now in doubt. Ticket sales have been slow, with FIFA last week releasing additional tickets even for top games featuring the hosts.
Terrorism attacks in Europe make security a top priority for Russian authorities who have special measures in place in St Petersburg, Moscow, Kazan and Sochi, four of the 11 cities being used for the 2018 World Cup.
A decree issued by President Vladimir Putin has also banned demonstrations and rallies between June 1 and July 12 without domestic intelligence approval.
While Germany coach Joachim Loew is resting his top players, Portugal have arrived at their first Confederations Cup appearance with world player of the year Cristiano Ronaldo their talisman as they hope to follow up Euro 2016 success with a triumph in Russia.