Romantics will pin their hopes on fourth-division Cambridge United when the League Two minnows host Manchester United in the most evocative tie of this weekend's FA Cup fourth-round matches.

United, who beat third-tier Yeovil Town in round three, sit 76 places above Cambridge in the English league system, but their manager Louis van Gaal has braced his players for a searching physical examination at the 8,100-capacity Abbey Stadium in eastern England.

The Dutchman has already seen his side humiliated 4-0 by third-tier Milton Keynes Dons in the League Cup and Cambridge manager Richard Money has admitted that his eyes grow wide at the thought of a similar exploit.

"I'm from a generation where there wasn't anything bigger than the FA Cup and I think this season we've seen a return to the spirit of the competition," said the former Liverpool player.

"The match will generate income, but for the players it's a chance to go into football folklore. We're not thinking we've got no chance."

Van Gaal has revealed that left-back Luke Shaw and striker Robin van Persie are both in contention to play after injury, but he baulked at press reports that new goalkeeper Victor Valdes will be handed his debut.

"I find it unbelievable how the media can write that," Van Gaal told MUTV. "I don't want to say anything about my line-up until just before the game."

While the last of United's 11 FA Cup triumphs came in 2004, Chelsea are bidding for a fifth success in nine years ahead of their home game with third-tier Bradford City on Saturday.

Jose Mourinho's side remain in contention for four trophies after drawing 1-1 at Liverpool in the first leg of their League Cup semi-final on Tuesday and goalkeeper Thibaut Courtois says the players have no trouble switching their focus from competition to competition.

"At the moment we are playing well in all of the competitions," the Belgium international told the club website.

"We're in the semi-final (of the League Cup), we're top of the league, on Saturday we have an important game in the FA Cup, which we have to win, and in the Champions League we will soon be playing Paris Saint-Germain, which will be hard.

"I think we have the team to win everything, but obviously there are other teams which can do the same."

Resurgent Liverpool, unbeaten in nine games in all competitions, face a reunion with former striker Emile Heskey on Saturday when they welcome second-division Bolton Wanderers to Anfield.

The 37-year-old former England striker joined Bolton in December after a two-year spell with Australian club Newcastle Jets.

"Emile has been fantastic since he walked through the door," said Bolton manager Neil Lennon, whose side are currently 15th in the Championship.

"He had a bit to prove when he came back here and he's doing that. There's plenty of football left in him and he's been a big bonus for us."

Manchester City also face Championship opposition in the form of Middlesbrough, while there are two all-Premier League ties, with Southampton entertaining Crystal Palace and Leicester City visiting Tottenham Hotspur.

Holders Arsenal, meanwhile, will approach their trip to second-division Brighton and Hove Albion on Sunday with renewed vigour after an impressive 2-0 victory at Manchester City in the Premier League last weekend.

"For us the challenge is to turn up with the same spirit and show that we can be consistent with our attitude game by game," said Arsenal manager Arsene Wenger.

"In the FA Cup, god knows that is needed. We know that it will be another big challenge for us to go there and come home with a positive result."

Wenger has revealed that German playmaker Mesut Ozil is likely to start at the Amex Stadium as he steps up his rehabilitation following a three-month absence with a knee injury.