Chelsea begin their defence of the FA Cup with what should be a routine home game against second-tier club Watford on Sunday,and manager Carlo Ancelotti has to decide whether to rest Michael Ballack,John Terry and Frank Lampard. With the Premier League campaign taking a break at the halfway stage,the focus turns to the third round of the cup and the topflight teams have largely managed to avoid each other as they enter the competition. That puts the coaches into a dilemma as they decide whether to run the risk of disrespecting the games oldest and most prestigious cup competition by resting their best players. Ancelottis team lead the Premier League by two points,and the Italian may well give some of the key players a break and take a look at some of his backup squad,especially those who have made few starts. Together,we took this decision to maintain this squad because we think this squad is a good squad,is able to play the games we have in January,and we have a possibility to give an opportunity a great opportunity to the young players if its necessary, he said. Manchester United hold the record of 11 FA Cup triumphs and have a tricky home game against runaway League One leader Leeds on Sunday. With his team just behind Chelsea in the Premier League and with a League Cup semi-final meeting with neighbours Manchester City to come,manager Alex Ferguson will probably give the likes of Wayne Rooney,Paul Scholes and Nemanja Vidic a rest. Likewise,Liverpool are likely to let Fernando Torres and Steven Gerrard sit out Saturdays visit to Reading,another team from the League Championship who have never won the cup.