Preview: Four things to look out for on Spain's matchday 15

MADRID, Dec. 8 (Xinhua) -- Following are the four things to look out on LaLiga this weekend, while Barca face a tricky visit to Villarreal and Atletico Madrid take on a Betis side that leaks goals:

1. Real Madrid to make case for the defense?

Fourth place Real Madrid entertain fifth place Sevilla with their defense in ruins: Sergio Ramos and Dani Carvajal are suspended, while Rafael Varene and Jesus Vallejo have muscle injuries leaving Nacho Fernandez as the only fit central defender. To complicate matters yet more for Zinedine Zidane, Casemiro, who could play in central defense, is also suspended meaning the coach will have to find an emergency solution for a vital game both sides need to win in order to keep in touch at the top of the table.

Marcos Llorente could be an option, although he has not played in the role for a long time, while Matteo Kovacic could get a chance in central midfield, but against a Sevilla side in form it is not the moment Zidane would have chosen to make experiments.

2. Villarreal another possible banana skin for Barca?

Last weekend saw league leaders, FC Barcelona drop two points with a draw at home to Celta Vigo, this weekend they face another possible banana skin when Ernesto Valverde leads his side down the coast to Villarreal.

Villarreal go into the match after three straight defeats, including a Europa League tie in which coach Javier Calleja gave the chance to eight B-team players, but until a fortnight ago were clearly in the ascendant.

They will be without the injured Carlos Bacca, but Cedric Bakambu is a striker who will cause problems to Barca' s only fit pair of central defenders, Gerard Pique and Thomas Vermaelen and if Barca do drop more points, the pressure will be well and truly on.

3. Atletico to pile the pressure on Setien?

In the middle of October things were looking good for Betis, under new coach Quique Setien they were playing exciting open football and scoring goals. Even a 6-3 home defeat to Valencia couldn't stop the feel-good factor as they battled back from 4-0 down to almost claim a point.

However one win in six games (against struggling Alaves) has well and truly seen the wheels fall off at Betis and a Cup exit at home to second division Cadiz has increased the pressure on their coach.

Although Betis' start to the season means they still sit in mid-table, this is not the time they would have chosen to entertain an Atletico Madrid who remain unbeaten in the league and whose strikers, Antoine Griezmann, Kevin Gameiro and Fernando Torres are returning to form.

Defeat on Sunday and Betis fans will start to look down, rather than up the table and Setien can start to worry about his future.

4. Celta to repeat Camp Nou feats in Mestalla?

Celta's draw away to Barca last weekend was a big surprise to some, but a look at how Juan Carlos Unzue' s men have improved over the past month or so and the quality of their squad means they always had the capacity to spring a shock.

Celta follow up their visit to Barcelona looking to go one better against second place Valencia and may have a chance on Saturday night.

Injuries have started to hit the Valencia squad and they are without Goncalo Guedes, Ezequiel Garay and Jeison Murillo, while top scorer Simone Zaza is at half speed with a knee problem.

Those absences cost Valencia defeat away to Getafe last Sunday and if Iago Aspas, Pione Sisto and Maxi Gomez have a good day on Sunday, there is no reason Celta can't spring another surprise, which maybe isn't such a surprise after all. Enditem