Barcelona's Lionel Messi Madrid - Arab Today Barcelona could be boosted by a return to the top of La Liga just three days before they host Manchester City in the Champions League with a win away to Valladolid on Saturday. The Catalans trail leaders Real Madrid by a point, but with Los Blancos not in action until Sunday evening when they host Levante, Barca can retake top spot for at least 24 hours. The Spanish champions have had another unsettling week off the field as captain Carles Puyol announced he would be leaving the club at the end of the season. Marc Bartra is one of those who stands to benefit from Puyol's departure as the 23-year-old will move up the pecking order in central defence. However, he insisted he will miss the guidance Puyol has given him as he has come through the ranks at the Camp Nou. "He has helped me a lot on the field. After every attack he gives me advice and after each match or training session too. He has been fundamental, not just with me but the whole team," he said. Bartra is expected to start on Saturday as Gerard Pique remains sidelined by a calf injury. And Bartra is determined to make the most of any opportunity he is handed by Barca boss Gerardo Martino. "I am very aware of where I am, which is the first team at Barcelona where almost nobody is guaranteed to start. "This year I have lived through both situations of playing very little and then playing a lot of games in a row. "With the coach, none of the 20 of us in the first team know whether we are going to start or be on the sidelines. He has managed things very well because every week you think you have a chance to start." Despite holding a 2-0 advantage from the first leg of their last 16 tie against City, Martino is expected to continue rotating his squad with the English side's visit in mind as Pedro Rodriguez and Andres Iniesta could come into the side that started the 4-1 win over Almeria last weekend. Even if Barca do emerge victorious at the Jose Zorilla, Madrid can retake top spot when Levante visit the Santiago Bernabeu on Sunday Los Blancos remain in the fight for titles on three fronts with just over two months of the season remaining and captain Iker Casillas admits they are targeting a first treble in the club's history come the end of the campaign. "Right now we are in a privileged position. We are outright leaders in the league, in the final of the Cup and, baring a disaster, we will be in the quarter-finals of the Champions League," he told the club's website. Marcelo and Dani Carvajal are expected to retake their places at full-back after making a positive impression as substitutes in Real's 2-2 draw away to local rivals Atletico Madrid last weekend. Otherwise, Real boss Carlo Ancelotti is likely to name an unchanged side as his team don't return to Champions League action until next week. That draw at the Vicente Calderon last weekend left Atletico still three points adrift of Real in third place. Diego Simeone's men have the toughest test of the title contenders on paper this weekend as they travel to Celta Vigo on Saturday. Los Rojiblancos will also have to do without top-scorer Diego Costa as he is suspended after picking up his fifth booking of the season against Real last time out. Fixtures (all times GMT) Saturday Valladolid v Barcelona (1500), Real Betis v Getafe (1700), Celta Vigo v Atletico Madrid (1900), Granada v Villarreal (2100) Sunday Espanyol v Elche (1100), Almeria v Sevilla (1600), Real Madrid v Levante (1800), Valencia v Athletic Bilbao (2000) Monday Osasuna v Malaga (1900), Real Sociedad v Rayo Vallecano (2100) Source: AFP