62' A simple pass down the line has En-Nesyri chasing down on goal. The angle is against him but he spots Vidal all alone in the box. The full-back is let down by a terrible first touch, denying him the chance to get a shot away.
60' Twelve of the 37 goals Lionel Messi has scored against Sevilla for Barcelona have come after the 75-minute mark.
58' Vidal just about gets his head to a deep delivery as Barca continue to knock on the door for an equaliser. The subsequent corner is pretty terrible, the ball going straight out of play without a touch.
56' Sevilla have lost their rhythm in the second half. Barca deserve credit for that but the Catalans just cannot find a way through at the moment in this entertaining first leg.
54' BOUNOU DENIES MESSI AGAIN! This is sublime from Messi. He takes the ball past one Sevilla player, inside another and then tees up De Jong. The Dutchman realises he is better off playing it back to Messi and the forward's shot is creeping into the bottom-left corner, if not for Bounou's low save.
52' GREAT DEFENDING! Barcelona are turning the screw. Carlos blocks Dembele's low cross but the danger stays alive for the visitors. De Jong tries to wriggle through but Kounde refuses to let the midfielder past and Barca must settle for a corner.
50' Messi's long-ranger is blocked by a Sevilla player. It is end-to-end stuff now in Seville!
49' CHANCE! Barca are once again exposed at the back and the ball drops for Rakitic to shoot 18 yards out. He takes his time but ends up hitting the ball right into Mingueza.
48' There have been plenty of challenges in the early stages of the second half. Barca are playing with a bit more urgency but Sevilla are looking strong at the back.
46' RESTART! Sevilla, leading 1-0 with 45 minutes of the first leg to go, get us back under way at the Estadio Ramon Sanchez-Pizjuan.
Koeman will not be impressed by his side's lack of creativity. Since Kounde's strike, Sevilla have been in control of the contest and perhaps should be two goals ahead at the interval. Trincao scored a late winner against Real Betis last weekend and is an option to come on at the interval for Barca.
Sevilla lead Barcelona 1-0 at half-time thanks to a fine solo goal from Kounde, the centre-back knocking the ball past Umtiti and guiding a shot away from Ter Stegen. Bounou had earlier produced a fine save down low to deny Messi, but Ter Stegen had to be alert at the end of the half to keep out Escudero's powerful drive.
45' + 2' HALF-TIME: SEVILLA 1-0 BARCELONA
45' + 1' WHAT A SAVE!! So nearly 2-0 to Sevilla! Barcelona are caught short at the back and Escudero is left in all sorts of space right on the edge of the box. He thumps a shot on target and Ter Stegen helps it over the crossbar with a strong hand.
45' One minute has been added on at the end of the first half. Barcelona could do with 15 minutes to regroup.
43' For all of Barcelona's possession, Sevilla continue to look the more dangerous side when they turn over the ball. There are just two minutes of the first half left to go.
41' CHANCE! En-Nesyri engages in a foot race with Umtiti. He speeds past the Barcelona defender but trips at just the wrong moment, meaning he does not manage to get a shot away with only Ter Stegen to beat.
39' There is a short stoppage in play now as the referee is having some difficulties with his headset. Sevilla are looking pretty comfortable as we fast approach the midway point at the Estadio Ramon Sanchez-Pizjuan.
37' Kounde is everywhere at the moment - Barcelona cannot contain the defender. The ball arrives in the Barca penalty area but En-Nesyri is beaten to it in the air by Mingueza.
35' There is no real urgency to Barcelona's game at the moment. Koeman will know that this tie cannot be won and lost today, so perhaps that is part of his thinking. 1-0 would not be a disastrous result for the visitors.
33' Koeman's side have had 55 per cent of the ball but have managed only a couple of shots on target. Kounde's impressive goal is the difference between these two in-form sides with more than three-quarters of the tie to go.
31' Barca are remaining patient in their pursuit of an equaliser. The visitors have created just one chance of note thus far, with Messi unable to beat Bounou from a one-on-one position.
29' Mingueza swings a leg at the ball in an attempt to take it off Rakitic but only succeeds in catching his opponent. The Barcelona defender is a little lucky to avoid being shown a yellow card there because Sevilla were on the counter.
27' That was a lovely touch from Kounde to take the ball around Umtiti, basically wiping out Barca's entire defence in the process. That was hardly the finish of a central defender, either!
24' Barca have dominated possession since that Kounde chance five minutes ago. A deep cross into the box is gathered by Bounou before Junior can get his head to it.
22' OVER! Messi and Dembele exchange passes on the edge of the box and the former decides to have a go from 20 yards. He gets his attempt all wrong, though, and the ball ends in the stands behind the goal.
20' JUST WIDE! Suso turns his opponent inside out and cuts the ball back for Kounde, who is stationed high up the pitch following a free-kick. The defender's first-time shot spins just past the post with Ter Stegen looking a little worried.
18' Alba gets in behind down the left for the first time today. The full-back is unable to pick out a team-mate but the loose ball falls to De Jong. He gets a shot away and it is blocked into the air before being cleared.
16' Barcelona forward Lionel Messi has not won any of his two previous competitive games against Sevilla defender Jules Kounde, failing to score in both matches from seven shots.
14' That really was a great save from Bounou to keep out Messi. The Barcelona forward did not exactly hit the ball straight at the Sevilla keeper - he picked his spot but came out second best on this occasion.
13' GREAT SAVE! This is nearly a sublime opener for Barcelona. Griezmann has space to shoot around 30 yards from goal but instead lifts the ball over the Sevilla defence and Messi meets it with a first-time shot. Bounou keeps out the attempt with his left leg.
11' Barcelona are certainly favouring their right-hand side, where Dembele is often picking up the ball in a bit of space. He sprays a pass into the feet of Messi and the Argentina international passes to Pedri, whose throughball for Griezmann is overhit.
9' The game is being played at a pretty frantic pace at the moment, but there has not yet been a chance or indeed a shot at either end of the field.
7' Rakitic slides the ball through for En-Nesyri but it has a little too much pace on it and Ter Stegen can collect.
6' The home side have now settled into the game. Julen Lopetegui's men are knocking the ball around without really looking to get it into advanced positions.
4' Barcelona have made a bright start to the match, pressing their opponents high up the pitch. Junior is looking lively in behind down the right.
3' Messi thinks about taking on the shot but is forced away from goal. It is instead worked to Dembele on the right and he has Junior on the overlap, though the attack soon breaks down.
1' KICK-OFF! Barcelona, the record 30-time winners of this competition, get us up and running at the Estadio Ramon Sanchez-Pizjuan.
Both sets of players are now out on the field and we are moments away from kick-off. These two sides are in superb form, winning their last 13 matches between them, but something has to give in this tight-to-call first leg.
Barcelona forward Lionel Messi has netted 37 goals in 40 games against Sevilla, scoring in four different competitions, four different grounds and against seven different goalkeepers:
Ronald Koeman has made five changes to Barcelona's starting line-up from the 3-2 win at Real Betis three days ago. Ronald Araujo, Miralem Pjanic and Martin Braithwaite all picked up injuries in that game and miss out on the squad today, while Puig and Lenglet drop to the bench. Junior has been drafted in at right-back, meaning Mingueza will partner the returning Umtiti in the heart of defence. Big-hitters De Jong, Pedri and Messi are also recalled.
Sevilla show three changes from their 3-0 win over Getafe in LaLiga last weekend. Fernando and Rakitic return to central midfield, the latter having served a one-match ban last time out, while January signing Gomez is recalled alongside En-Nesyri and Suso in attack. Torres and Gudelj drop to the bench, while injured winger Lucas Ocampos is not involved at all.
Subs: Matheus Fernandes, Inaki Pena, Neto, Clement Lenglet, Alex Collado, Ilaix Moriba, Trincao, Riqui Puig, Konrad De la Fuente.
BARCELONA XI (4-3-3): Marc-Andre ter Stegen; Junior Firpo, Oscar Mingueza, Samuel Umtiti, Jordi Alba; Frenkie de Jong, Sergio Busquets, Pedri; Ousmane Dembele, Lionel Messi (c), Antoine Griezmann.
Subs: Tomas Vaclik, Karim Rekik, Munir El Haddadi, Nemanja Gudelj, Oliver Torres, Luuk de Jong, Sergi Gomez, Franco Vazquez, Joris Gnagnon.
SEVILLA XI (4-3-3): Yassine Bounou; Aleix Vidal, Jules Kounde, Diego Carlos, Sergio Escudero (c); Joan Jordan, Fernando, Ivan Rakitic; Suso, Youssef En-Nesyri, Alejandro Gomez.
The home side have yet to concede in the five previous rounds to make it to this stage, most recently seeing off Almeria 1-0 in the quarter-finals. As for Barca, they salvaged extra time against Granada in the last round before prevailing 5-3 in a thriller.
Sevilla enter this contest on a seven-game winning run in all competitions, keeping a clean sheet in the last five of those, while Barcelona have themselves won six on the spin.
Hello and welcome to our live text coverage of the Copa del Rey semi-final first leg between Sevilla and Barcelona at the Estadio Ramon Sanchez-Pizjuan.