Barcelona have lost their last two in the league to blow the title race wide open, while they were also eliminated in the quarter-finals of the Champions League by Atletico Madrid on Wednesday night.
Valencia have only won one of their last five in the league, but that success came last time out as Pako Ayestaran picked up his first victory at the helm - a 2-1 home success over Sevilla.
What has happened to Barcelona? On March 16, the Catalan outfit had just beaten Arsenal to make the quarter-finals of the Champions League and were comfortably clear at the top of La Liga. Another treble was in reach, but the wheels seem to have fallen off over the last few weeks and serious damage has been done.
Indeed, Barcelona's hopes of becoming the first team since AC Milan in 1989 and 1990 to successfully defend the European Cup ended on Wednesday when they lost 2-0 at Atletico in the quarter-finals of the Champions League. The curse of the holders struck again as Luis Enrique's side bowed out 3-2 on aggregate.
The damage cuts deeper than the Champions League, however, with Barcelona also losing their last two in the league. A 2-1 defeat to Real Madrid on April 2 ended their 39-game unbeaten run in all competitions and they then lost 1-0 at Real Sociedad last weekend to throw the title race wide open.
Entering week 33, Barcelona hold a three-point lead over second-placed Atletico and four-point lead over third-placed Real Madrid, but both of the Madrid teams have very winnable matches this weekend. On Saturday, Real Madrid will travel to Getafe, before Atletico host Granada on Sunday.
In theory, Barcelona's lead could be cut to just one point by the time they take to the field against Valencia, but the Catalan outfit have been very strong at home this season - winning 14 of their 16 league matches and losing just once. They have also netted 55 times at Camp Nou in the league and conceded just 12 times in the process.
Lionel Messi, however, is currently on his worst run of scoring form for five years. The Argentine has not netted in his last five games for Barcelona and was once again out of sorts against Atletico. Neymar and Luis Suarez have also hit a dry patch and all three will be keen to return to the scoresheet this weekend.
Enrique's side will face Sevilla in the Copa del Rey final next month, but they cannot afford to take their eye off the ball in the league. After this one, they will travel to Deportivo La Coruna next week, before hosting Sporting Gijon and travelling to Real Betis before the end of the month. They will then welcome Espanyol on May 8, before ending the campaign with a trip to relegation-threatened Granada.
Recent form: WWWDLL
Recent form (all competitions): WDLWLL
There is no getting away from the fact that it has been a very disappointing campaign for Valencia, who currently sit 14th in the table - some 14 points away from the top six with just six games of the season left.
The experiment of Gary Neville just did not work, with the former Manchester United defender relieved of his duties at the end of March. His assistant - Ayestaran - has taken control of first-team affairs until the end of the season and the Spaniard picked up his first league win last time out - a 2-1 success over Sevilla at the Mestalla.
Mathematically, Valencia are not actually safe from the drop this season, but they have some winnable fixtures coming up, facing out-of-form Eibar and Getafe in their two after this one. They would have expected to be travelling to a confident Barcelona at this stage of the season, but that is simply not the case.
Los Che have only won nine of their 32 league games this season, however, and only managed 36 goals. They have only won one of their last five in Spain's top flight and only picked up five wins at the Mestalla all season.
Paco Alcacer is Valencia's leading scorer in the league this season with nine goals, while Dani Parejo has hit seven from midfield. Alvaro Negredo only has five, however, and the likes of Rodrigo and Santi Mina have struggled to make their mark for a team that were expected to challenge for the top four this season.
There will be a change of manager at the end of the campaign as Valencia attempt to return to former glories, and despite their struggles this term they still boast a squad full of talent. The former Spanish champions would not have relished a trip to Barcelona last month, but they might well fancy pulling off a surprise this time around.
Recent form: WLLLLW
Recent form (all competitions): LLWLLW
Following the defeat to Atletico, Enrique could make changes at both full-back and midfield, with Sergi Roberto and Rafinha both pushing for selection, should the latter overcome a slight hamstring problem.
Munir El Haddadi is also pushing for a start in the final third, but it seems unlikely that Enrique will take apart his attacking trident of Neymar, Messi and Suarez, despite their struggles in recent weeks.
Guilherme Siqueira and Antonio Barragan will continue in the two full-back positions, while Ruben Vezo could also come into the team in a wide midfield area, which would see the Portuguese given defensive duties.
Alcacer is once again expected to be given the nod over Negredo at centre-forward, while Sofiane Feghouli is expected to return to the XI after starting the Sevilla match on the bench.
Barcelona possible starting lineup:
Bravo; Roberto, Pique, Mascherano, Alba; Rafinha, Busquets, Iniesta; Neymar, Suarez, Messi
Valencia possible starting lineup:
Alves; Barragan, Mustafi, Abdennour, Siqueira; Gomes, Fuego, Parejo; Feghouli, Alcacer, Vezo
Head To Head
Sunday's meeting will be the fourth time that the two teams have met this season.
Barcelona were also 2-0 winners in the corresponding league match last season, but Valencia have won at Camp Nou in the league as recently as February 2014 - when they recorded a 3-2 success.
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We say: Barcelona 2-0 Valencia
Barcelona are on a poor run of form at the moment and confidence at Camp Nou will be low. They will be keen to bounce back from European disappointment, however, and it is difficult to imagine them putting in another lacklustre performance. Valencia have the players to hurt Barcelona, but we are backing the home side to return to winning ways this weekend with a routine 2-0 victory.