Lionel Messi strained a calf muscle in Barcelona training but expects to be sidelined for only a short time.
Lionel Messi has a minor calf strain and will not join Barcelona for their pre-season matches against Napoli in the United States.
Defeats to Napoli, Borussia Dortmund and Sevilla left Jurgen Klopp with mixed feelings about Liverpool's pre-season matches.
Pierre-Emerick Aubameyang put Arsenal ahead but an Ainsley Maitland-Niles own goal helped Barcelona bounce back in the Joan Gamper Trophy.
Arsenal have named Mesut Ozil and Sead Kolasinac in their squad to face Barcelona but Nicolas Pepe will not make his debut.
Diego Costa and Joao Felix again combined pleasingly but Diego Simeone needed a clutch of his Atletico Madrid youngsters to win in San Luis.
Chelsea's pre-season ended in a draw against Borussia Monchengladbach thanks to Ross Barkley's late penalty.
"Somebody has to think of the players" when it comes to starting the new football season so soon, according to Liverpool boss Jurgen Klopp.
Manchester United will be without Paul Pogba against AC Milan on Saturday, but he should be able to face Chelsea a week on Sunday.
Manchester United face AC Milan in Cardiff on Saturday, but Romelu Lukaku will be absent once again ahead of a reported move to Juventus.