The Catalan giants have sent Cornella and Rayo Vallecano packing in the tournament so far, and they are certainly the favourites to go all the way after Real Madrid and Atletico Madrid suffered shock exits in the earlier rounds.
Here, Sports Mole looks at how Barcelona could line up for their quarter-final clash with Granada.
Cup matches always offer managers the opportunity to shuffle the pack and rest some key names, and that is no different with Barca, but the visitors should still name a relatively strong lineup against their fellow top-flight outfit.
Barcelona had to make do without Sergio Busquets for the win over Athletic due to a suspension, but the veteran Spaniard is available here and it would be a surprise not to see him start.
Frenkie de Jong could make way for Busquets as Koeman keeps a daunting February schedule in mind when selecting his team, so the underwhelming Miralem Pjanic is also expected to be handed another start this week.
Barca could welcome Sergi Roberto back to the fold at right-back after he made his return from a two-month absence against Athletic, but Sergino Dest is also fit again to provide Koeman with another option in defence.
Junior Firpo was reportedly blocked from making a late exit by Koeman and has not been included in the squad to face Granada, so Jordi Alba - who scored an own goal at the weekend - will start again here.
Neto and Clement Lenglet could complete the changes in defence, while further up the pitch, Messi - who recently had an image of his contract leaked - will hope to strike for the 15th time against Granada.
However, the Argentine could be deployed on the left-hand side rather than up top if Martin Braithwaite is given the opportunity to impress, while Trincao and Riqui Puig will also look to start over fellow youngsters Pedri and Ousmane Dembele - both of whom could make an impact from the bench.