Luiz Felipe Scolari's men open their campaign to win the cup against League One opponents who are expected to bring 6,000 fans to west London.

Carvalho, who returned to action against Fulham on Sunday after two months out with a hamstring injury, is prepared for a tough examination against the Shrimpers.

"It is different, this competition. It is a big day for them and you have to prove you are better, you have to run as hard as them and you have to play with the ball because you have more quality," the Portugal international told the club's official website www.chelseafc.com.

"But you have to run as (much as) them. Sometimes they run a little bit more than us, they run like crazy and it is difficult - but after when our quality is coming and you prove inside you are better, normally it is one, two, three-nil.

"So let's see how it happens this time against Southend. The game will be difficult in the first 20 minutes and you have to play serious and play better than them to score goals."

Southend have been boosted by the signing of midfielder Jean Francois Christophe on a two-and-a-half-year deal from Portsmouth after a previous loan spell with the Essex club, and he is available to take on the Barclays Premier League giants.

"You know who you are going to be facing and you have to be ready," Christophe told the club's official website www.southendunited.co.uk.

"They have world-class players and in my position it could be Frank Lampard, Deco or John Obi Mikel we're up against but that's a great challenge for us.

"They are superb but at the end of the day it's still man against man. They have two hands and two feet just like the rest of us and we want to go there and give them a game.

"We are excited about it and have nothing to lose because they are big favourites."

Also fighting against the odds will be Coca-Cola League Two side Macclesfield, who host Everton at their Moss Rose ground.

Toffees midfielder Mikel Arteta is hoping the Merseysiders can follow up their Premier League win at home to Sunderland by taking their first step towards an FA Cup final appearance on May 30.

"The FA Cup means a lot because it gives you the chance to get to a final and win it, and get into Europe as well so we have to try really hard," the Spaniard told www.evertonfc.com.

"We haven't got the biggest squad but we were knocked out of the UEFA Cup which was a big disappointment so hopefully now we can have a good run in this and it will be a boost for the club."

Blue Square Premier strugglers Barrow are expected to take 7,000 fans with them to face Premier League opponents Middlesbrough at the Riverside Stadium, while new Nottingham Forest boss Billy Davies will watch his charges take on Manchester City at Eastlands. Caretaker manager John Pemberton will take care of first-team duties for the tie, with Davies starting work on Monday.

Plymouth boss Paul Sturrock admits his side's run of one win in eight Championship games is relegation form but claims his team's performances have warranted better results as they prepare for a glamour tie against Arsenal at the Emirates Stadium.

"Our standard of performance has been much better than the results have shown against Birmingham, QPR and Cardiff the other day," he told the club's official website, www.pafc.co.uk.

"I would like to think we would bring some of that into the game but the pressure is all on Arsenal, and we have got to try and feed off that."

Sturrock's squad will be boosted by the arrival of Scotland Under-21 international David Gray on loan from Manchester United.

Among Saturday's other ties are the all-Premier League encounters between Hull and Newcastle and Sunderland and Bolton.

Holders Portsmouth host Bristol City, last season's semi-finalists Barnsley take on West Ham at Upton Park, non-league Histon host Swansea while Liverpool travel to Preston in the Saturday evening kick-off.

Aston Villa take on Gillingham at Priestfield on Sunday while Manchester United are away to Southampton. Blue Square North side Blyth Spartans could cause one of the biggest shocks in the competition's history if they can overcome Blackburn on Monday night.