Uruguay's game against the reigning European champions will take place at Sochi's Fisht Stadium on Sunday (4am AEST).

"I don't know what tomorrow's match will look like. Both Portugal and ourselves have good enough players, Tabarez said.

"Do you think that it can transform into a match that will be boring? We don't think about it. Boring or not, if we win, we'll be happy."

The head coach added that there were no easy matches at the World Cup.

"We are preparing seriously, as always," he said.

Of course, we know Portugal players, and many of our footballers have played against them at a club level. I don't think we need to change something drastically, because it creates doubt within the team."

The 2018 FIFA World Cup kicked off on June 14 and will continue until July 15, with the matches being played in 11 cities across Russia.