Madrid, Feb 6 (IANS): With plenty of tension as well as controversy promised, Atletico Madrid and Real Madrid kick-off on the weekend at the Vicente Calderon here Saturday afternoon.

The two sides clash for the sixth time this season and if previous encounters are anything to go by, it could be a difficult afternoon for the referee but also for Real Madrid coach Carlo Ancelotti, reports Xinhua.

Ancelotti's side cross Madrid with a seven point lead over their neighbours in La Liga, knowing that victory will leave Atletico trailing in their wake.

However, Ancelotti also knows his side have failed to beat their neighbours in five games this season and is also missing experienced players for the game due to a mix of injury and suspensions, with Marcelo sanctioned by the Spanish Football Association (RFEF) after seeing his fifth booking of the season.

Meanwhile, James Rodriguez will be out of action for two months after undergoing an operation on a broken metatarsal bone in his right foot Thursday, central defenders Sergio Ramos (hamstring) and Pepe (rib) are also out of action, and Fabio Coentrao also has a muscle problem.

Those absences will see Ancelotti bring Cristiano Ronaldo, who is available after suspension, back for James, while Alvaro Arbeloa will play at left back and the adaptable Nacho Fernandez will play alongside Rafael Varene in central defence.

Ancelotti admits the injuries have robbed his side of much-needed experience against an Atletico that normally plays at the limit of the law in midfielder and defence order to get a result.

While they are rock-solid at the back, Atletico are now functioning in attack with Mario Mandzukic, Antoine Griezmann and Fernando Torres posing a threat to any rival. Torres has already scored twice against Real Madrid following his triumphant return to the club as Atletico dumped Real Madrid out of the King's Cup in January.

Torres said Friday that the change in Atletico's mentality was that in the past they used to go onto the pitch "to see what happens, now we go out to win".

Meanwhile, Mandzukic poses a fearsome threat from set pieces (something Real Madrid struggle to defend against) and Griezmann will use his pace to look to punish any loss of possession in the Real Madrid midfield.

It looks to once again be finely balanced with the game likely to be decided by details and every decision by the referee put under the microscope.