Barcelona win a free-kick in a decent position on the right, which Memphis Depay takes.

The ball loops up high into the air and Philippe Coutinho tries to hit it on the volley, but fails to make proper contact.

Nico Gonzalez races clear moments later but can't direct his shot on target.

Luuk de Jong and Gavi are warming up on the touchline.

When will Ronald Koeman make his first throw of the dice?

Back under way.

Rayo are 45 minutes away from their first win over Barcelona since December 2002.

Mallorca lead Sevilla 1-0 in the other game going on in La Liga at the moment.

Real Betis' match against Valencia is about to kick off, with Real Madrid's game at home to Osasuna getting under way at 20:30 BST.

Over 70% possession for Barcelona in that half but they've failed to register a shot on target.

Plenty for Ronald Koeman to ponder as the half-time whistle goes.

Philippe Coutinho lifts a hopeful ball over the top of the Rayo defence for Sergio Aguero to chase, but it's into the arms of Stole Dimitrievski.

Sums up Barca's half, that.

Alvaro Garcia goes close for Rayo, who just about deserve their narrow lead after surviving that spell of Barcelona pressure.

Barca have yet to win on their travels this season. Can they turn things around here?

Why didn't he shoot?

Nico Gonzalez finds Memphis Depay, who is in a great position to shoot on the left corner of the area.

The Dutchman instead tries to pick out Sergino Dest at the far post, but the ball is cleared and Nico Gonzalez's follow-up effort is blocked.

Should be 1-1.

Memphis Depay does brilliantly on the left before firing in a low ball across the six-yard box. Sergino Dest is first to the cross but somehow fails to hit the target.

That's a poor miss.

Marc-Andre ter Stegen's clearance is straight at Isi Palazon, who takes a touch before blazing a powerful effort over the crossbar.

Barca need to regain their composure.

The Estadio de Vallecas is absolutely bouncing.

Barcelona look a little shell-shocked after that goal. They were so comfortable before Falcao struck.

Just approaching the half-hour mark at the Estadio de Vallecas. Can Barcelona make their dominance count?

Sergino Dest cuts on to his left foot and unleashes a fierce drive towards the bottom corner, but it's into the side-netting.

The majority of Barcelona's attacks so far have come down the right-hand side.

Memphis Depay attempts to thread a ball through to Philippe Coutinho, but the former Liverpool man fails to sort his feet out and Rayo clear the danger.

Coutinho has been quiet so far.

Oscar Trejo is shown the game's first yellow card for a late challenge on Nico Gonzalez.

The hosts are chasing shadows at the moment.

That wasn't too far away!

Radamel Falcao turns onto his left foot and tries his luck from the edge of the box. His shot takes a slight deflection off Gerard Pique and Marc-Andre ter Stegen has to tip it behind.

The resulting corner comes to nothing.

This is much better from Barcelona. The visitors are finding plenty of space in between the lines. Rayo are struggling to cope at the moment.

Sergio Busquets tries to find Memphis Depay with a looping ball into the box, but there's too much on it and Rayo have a goal-kick.

Penalty? No!

Nico Gonzalez marches forward and threads a delightful pass into the path of Sergio Aguero, who takes a touch before going down under a challenge from Stole Dimitrievski.

Aguero casts a hopeful glance at the referee, but there was little contact.