The Spanish champions have beaten Sevilla and Real Madrid in their last two matches to rise to the top of La Liga, and they will fancy their chances of overcoming a Rayo side that sit down in 19th spot in the division.
Rayo spent five straight seasons in La Liga between 2011 and 2016 before dropping into the Segunda Division. They finished a disappointing 12th in the second tier at the end of the 2016-17 season, but secured a return to La Liga by winning the Segunda Division last term.
The small team from Madrid have long been seen as the great entertainers, but it does appear that they are in for a difficult season. Indeed, a record of one win, three draws and six defeats from their first 10 matches of the 2018-19 campaign has left them down in 19th spot in the division.
Rayo have only managed 10 goals in their 10 league matches this season, and have conceded 20, which is the second-worst defensive record in the division behind basement side Huesca.
The capital outfit started their 2018-19 La Liga season with a 4-1 home defeat to Sevilla, before losing at Atletico Madrid one week later. They did record a 1-0 win over Huesca on September 14, but that remains their only league success this term.
Indeed, they conceded five at home to Alaves on September 22, and have lost three of their last four to Leganes, Getafe and Girona. Rayo have also not won in front of their own supporters this season, and have worryingly already shipped 14 home La Liga goals in the early weeks of the campaign.
When considering that Rayo's next three are against Barcelona, Villarreal and Valencia, it is difficult to see where the points are coming from. Los Vallecanos are always good value in terms of entertainment, but they must find a way of picking up some points ahead of the winter break in Spain.
The team's leading scorer this season is on-loan Real Madrid forward Raul de Thomas. The 24-year-old has three La Liga goals to his name this term, and will be hoping to do his parent club a favour on Saturday.
Recent form: DDLLDL
Recent form (all competitions): DLLDLD
It was not so much a 'crisis', but Barcelona did go four La Liga games without a win between September 23 and October 7. Three of those matches ended in draws, and they also suffered a 2-1 defeat at Levante on September 26. There were some murmurs of discontent, but it does appear that the Catalan outfit are back on the right track.
Indeed, a 4-2 home success over Sevilla on October 20 saw Barcelona move to the top of the table. The victory came at a price, however, with Lionel Messi picking up an arm injury which was to rule him out of the upcoming matches with Inter Milan and Real Madrid in the Champions League and La Liga respectively.
Barcelona had no problems putting two wins on the board, however, as they recorded a 2-0 success over Inter before thumping Real Madrid 5-1 in El Clasico last weekend. It was a performance and indeed result that saw Barcelona send out a message to the rest of the division that they are once again the team to beat this season.
As it stands, Ernesto Valverde's side top the table on 21 points. They are, however, only one point clear of second-placed Alaves and just two clear of third-placed Atletico Madrid. Even Real Madrid down in ninth are just seven points off the summit, which shows that Barcelona have not been without their issues this term.
Valverde's team will play just three La Liga matches in the month of November, travelling to Rayo and Atletico either side of a home game with Real Betis. The Catalan giants stormed to the Spanish title last season, and will fancy their chances of finishing top of the pile once again.
That said, Barcelona have dropped points in two of their four away league matches this term, and have actually only scored five times on their travels, which is in contrast to their 23 at Camp Nou. Messi will again be absent this weekend, which places a lot of pressure on Luis Suarez to find the back of the net.
Barcelona, who beat Cultural Leonesa 1-0 in the Copa del Rey on Wednesday, have scored 24 times in their last five games against Rayo, however, and are the overwhelming favourites to secure all three points.
Recent form: DLDDWW
Recent form (all competitions): WDWWWW
Rayo boss Michel shuffled his pack for the 2-2 draw with Leganes in the Copa del Rey on Tuesday night. De Tomas and Gael Kakuta were among those to be left out of the cup match, but both will return for this one.
As for Barcelona, Messi has returned to training following a fractured arm, but it is unlikely that the Argentine will be risked for this match. Samuel Umtiti has also stepped up his recovery from a knee problem, although the Frenchman is still unavailable.
There is expected to be 11 changes from the team that started against Cultural Leonesa in the Copa del Rey, with Rafinha due to be given the nod ahead of Ousmane Dembele, who is currently being linked with a move away from the club.
Rayo Vallecano possible starting lineup:
Garcia; Advincula, Galvez, Amat, Moreno; Imbula, Comesana, Trejo; Kakuta, De Thomas, Embarba
Barcelona possible starting lineup:
Ter Stegen; Roberto, Pique, Lenglet, Alba; Arthur, Busquets, Rakitic; Coutinho, L Suarez, Rafinha
Head To Head
As mentioned above, Barcelona have scored 24 times in the last five meetings between the two teams, including 16 in their last three.
The Catalan giants also put seven unanswered goals past Rayo when they made the trip during the 2011-12 La Liga campaign, which is an indication of the task facing the home side this weekend.
We say: Rayo Vallecano 0-3 Barcelona
It is very difficult to predict anything other than an away win this weekend. Rayo concede goals for fun, and we expect Barcelona to collect a very comfortable three points on Saturday night.