Barcelona host El Clasico rivals Real Madrid as the pair meet at the Nou Camp in the opening leg of their Copa del Rey semi-final on Wednesday.
The bitter opponents will clash three times in the coming weeks as they battle for supremacy at the end of the season.
Here, Press Association Sport takes a look at the major talking points ahead of the game.
Will Lionel be fit to make it a Messi night for Madrid defence?
Lionel Messi has scored 12 goals in his last nine games.
The diminutive Argentinian is in fine form but suffered a minor leg injury in Saturday's LaLiga draw with Valencia.
While Messi trained on Tuesday evening, Barca coach Ernesto Valverde would not be drawn on whether the 31-year-old would be risked but he was included in the squad.
What is ailing Bale?
Gareth Bale returned from a calf injury at the weekend having missed Real's eight games before the 3-0 win over Alaves.
The Wales international did not look at his best in that win and there is a suggestion in some quarters that he is struggling to fill the sizeable void left by Cristiano Ronaldo's exit.
Bale will be hoping for another chance to provide the sort of heroics he did off the bench in last season's Champions League win over Liverpool.
Familiarity breeds contests
There is not much these two Spanish giants do not know about one another.
But this is the first of three games between Barcelona and Real Madrid over the next 24 days, with the second leg of the semi-final and the LaLiga clash – both at the Bernabeu – still to come.
Wednesday's first game will be a good barometer for both managers to judge what is needed to secure positive results in the coming month.
Squad goals
Although it is a cup semi-final, both Valverde and Real Madrid counterpart Santiago Solari may look to make some changes.
Real in particular, need to keep an eye on the league – where they sit third, eight points adrift of leaders Barcelona – and face a Madrid derby against second-placed Atletico at the weekend.
That could lead to some fringe players being given a chance to shine at the Nou Camp – with the likes of Brahim Diaz, Isco and Marcos Llorente hoping for the call.
Another five-star showing for Barcelona?
Barcelona have been the team to beat in LaLiga once again this season.
Their 5-1 thrashing of Real Madrid earlier in the campaign led to Julen Lopetegui losing his job as coach just months after taking over.
Luis Suarez bagged a hat-trick on a night to remember for Barcelona but their Clasico rivals have improved since then and will be keen to exact a modicum of revenge on Wednesday.
