Hosts face Spain as Croatia take on Denmark today

MOSCOW, June 30 (Reuters): A World Cup last-16 match between Spain and Russia would have seemed like a woeful mismatch a month ago but Sunday's game in Moscow is now much more difficult to call thanks to the 2010 winners' underwhelming campaign and the hosts' blistering start.

Spain's preparations for the World Cup were thrown into turmoil after coach Julen Lopetegui was sacked and replaced by Fernando Hierro just days before the start of the tournament.

Hierro's side topped Group B but picked up only five points.

Russia, the lowest ranked team in the tournament, dispelled the doom and gloom by blitzing Saudi Arabia 5-0 and beating Egypt 3-1 to reach the knockout phase for the first time since the collapse of the Soviet Union.

While Stanislav Cherchesov's side were brought back to earth by a 3-0 defeat to Uruguay, they could cause Spain problems at a partisan Luhzniki stadium if they can rediscover the energy that propelled them to those first two group wins.

Spanish defender Dani Carvajal says his side, who drew 3-3 with Portugal and 2-2 with Morocco, must tighten up at the back against the Russians.

"On Sunday we have a very difficult game against the host nation, who scored eight goals in two games and who will have the whole country behind them," Carvajal said.

"Russia is a strong and quick team and we have to be very wary of giving the ball away. We have to be very focused and set ourselves up to exploit their weaknesses and capitalise on their errors."

However, Carvajal said teams will be forced to attack more in the knockout stages, where he expects Spain to come out from the shadows and up their game.

Spain and Russia played out a thrilling 3-3 draw in a friendly last November, while their last competitive meeting came at the Euro 2008 semi-finals, where the Spaniards ran out 3-0 winners.

Russia's veteran defender Sergei Ignashevich is one of three surviving members of that team in the current squad, and he said his side had studied how Iran and Morocco managed to trouble Spain defensively.

Meanwhile, Croatia go into Sunday's last-16 match against Denmark with a 100 per cent record at this World Cup but the Danes are vowing to shake off their dull image and cause a surprise.

At stake in the match at the Nizhny Novgorod Stadium, the same venue where the Croats thumped Argentina 3-0 in the group stage, is a quarterfinal against former world champions Spain or tournament hosts Russia.

Captained by experienced playmaker Luka Modric, Croatia also beat Nigeria and Iceland to top Group D and are now dreaming of going one better than their performance at the 1998 tournament where they reached the semi-finals. The Danes, meanwhile, are happy to continue flying under the radar despite being on a 17-match unbeaten run.

Having scored just two goals in navigating their way out of Group C as runners-up, the Danes expect to open up on Sunday. Denmark coach Age Hareide has promised a more entertaining, attacking style against Croatia after their fans jeered them in a bore draw against France. For that creative energy, he will rely heavily on key player Christian Eriksen.