Alcacer, 23, started and scored in Barcelona's 3-1 win over Deportivo Alaves on 27 May.
Hector Bellerin agreed a new contract with Arsenal until the summer of 2023.
Barcelona looking to end disappointing season on a high by clinching Copa del Rey crown.
Red Devils keen to offer new contract to Herrera, reports say.
Barcelona finished three points behind their arch-rivals in La Liga standings.
A 2-0 win over Malaga sealed the title for Zinedine Zidane's side.
Barcelona must beat Eibar to have any chance of retaining the La Liga title.
The 22-year-old will represent his country at the Under-21 Euros in Poland in June.
Vinicius Junior, 16, is eligible to move to Europe in the summer of 2018.
Coutinho is having his best season with Liverpool in terms of goals scored since his arrival in 2013.
Barcelona looking to hold on to top spot in La Liga with victory at Estadio Gran Canaria.
Neymar signed a new five-year contract with Barcelona in 2016.
Atletico Madrid defender Hernandez, 19, is on a season-long loan at Deportivo Alaves.
Reports in Spain claim five-time Ballon d'Or winner rejected €30-€35m offer.
Chelsea manager says Mbappe still has a lot of room to further improve his game.
Barcelona will be looking to maintain top spot in La Liga.
The Dutchman told a Catalan newspaper he dreams of one day managing at the Nou Camp.
Bellerin signed a new deal at Arsenal last November and it will keep him at the club until 2022.
Mbappe has also attracted attention from Real Madrid and Arsenal after impressing for Monaco.
Barcelona cannot afford to slip up against city rivals at Cornella-El Prat.
Barcelona can go three points ahead of Real Madrid with victory over Osasuna.
Neymar, 25, has more than four years left on his Barcelona contract.