Barcelona will be keen to avoid a case of 'after the Lord Mayor's show' when they take on Xerez just three days after defeating Real Madrid in 'El Clasico'.

Barca replaced Madrid at the top of the table after Sunday's 1-0 win over Manuel Pellegrini's men at the Nou Camp, and they can extend their advantage at the summit to five points in their re-arranged fixture against rock-bottom Xerez.

The game was initially meant to be played during the 15th round of Primera Division fixtures on the weekend of December 19-20, but due to Barca's commitments in the FIFA Club World Cup this month the game was brought forward.

"If we want to be champions, and have another very good year, then we need to keep our motivation against Xerez. Last year we found it tough against the teams who were lower down in the table," said Guardiola,

"We are the only ones playing and we can take advantage of that and open up a gap. If we want to be champions, we will see it tomorrow.

"There was a lot of tension for the game against Real Madrid, which takes a lot out of you physically and mentally.

"We have to make sure we don't let the tension drop. There were a lot of doubts before the Inter game (2-0 win last week) and now everybody's confident. The players have always responded since I came here."

Regarding their opponents on Wednesday, Guardiola added: "Xerez have an interesting defensive organisation and I've been told the pitch may not be in very good condition."

Guardiola has decided to leave out centre-backs Gerard Pique and Gabriel Milito - who got the green light to return to first-team action yesterday after 580 days out with a knee injury - for the match, while midfielder Sergi Busquets is suspended following his red card against Madrid.

Barca make the trip south having lost just one match in all competitions this season, which was their surprise 2-1 home defeat to Rubin Kazan in the Champions League.

It is a totally different story for Xerez, though.

They have won only one match since being promoted to the top flight for the first time in the club's history, and were also dumped out of the Copa del Rey by Osasuna.

At the weekend they were thumped 5-1 by Getafe, a result which saw them return to the foot of the Primera Division standings, three points adrift of Atletico Madrid and safety.

Despite the obvious gulf in class between the two teams, Xerez coach Jose Angel Ziganda insists his side should not be dismissed as cannon fodder for mighty Barca.

"It's not mission impossible to win. We are fortunate to have the chance to play and enjoy a game against the best team in the world. We will try to have a good game and fight to get something positive out of the match," said Ziganda.

"Barcelona are not going to win every single game of the season. We shouldn't think about anything else. We need to compete well and fight for the victory."