Stanislav Cherchesov's side thrashed Saudi Arabia 5-0 in the first game of the tournament before beating Egypt 3-1 to reach the knockout stage for the first time.

"The Russian team, I'm not surprised, I know the mentality of the Russians, it's a home World Cup. Uruguay was a strong team, but Russia played only with 10 players. They were giving their heart, which they were not doing two years ago in France (at UEFA Euro 2016), and I think the Russian football fans can be happy to have a national team like this," Matthaus told journalists.

Russia were beaten 3-0 by Uruguay in their final Group A game and will take on 2010 World Cup winners Spain in the last 16.

"Now a very difficult game against Spain, and I think think that Spain is the favourite, but in football, you saw it in the last two weeks, everything is possible," Matthaus said.

Matthaus captained West Germany to victory at the 1990 FIFA World Cup in Italy and played a record 25 games at five consecutive tournaments.