Mane scored for the first time in a Reds shirt and Origi grabbed an assist and a goal in the space of a minute, but Sturridge and James Milner gave Jurgen Klopp a potential headache before the big Premier League kick-off.

There are once again question marks over Sturridge's fitness ahead of next week's opener at Arsenal after the England striker missed out with what the club explained was a slight hip injury.

And Klopp was dealt another blow when Milner, who was playing in Liverpool's problem left-back position, limped off moments before half-time.

Nevertheless, the Anfield boss would have been hugely encouraged by his side's display against Lionel Messi, Luis Suarez and co.

Suarez was facing his old club for the first time since moving to the Spanish giants having scored 82 goals in 133 appearances during three-and-a-half memorable years with the Reds.

The Uruguayan was cheered by Liverpool's fans and hugged his former team-mates, while the convivial atmosphere at the International Champions Cup friendly was also evident on the touchline where Klopp and opposite number Luis Enrique chatted warmly.

Klopp took in much of the action perched on an icebox, while Enrique, dressed in jeans and a T-shirt, could hardly have been more casual.

Mane, Liverpool's £34m summer signing from Southampton, looked eager to impress and got off the mark thanks to a slick move after 15 minutes.

Adam Lallana stole the ball from Munir on the halfway line and surged forward, playing a neat one-two with Roberto Firmino before setting up Mane to slot home.

Suarez and Messi almost combined to grab an equaliser but the latter's finish from his strike partner's flick cannoned back off the far post.

Milner then denied Arda Turan with a last-ditch tackle and Simon Mignolet spread himself to keep out a trademark Suarez volley.

After Milner had been withdrawn, Klopp introduced Jordan Henderson, Origi and Kevin Stewart at the break, and their impact was instant.

Just a minute had gone when Origi darted down the right and crossed for Henderson, who bundled the ball home with the help of former Red Javier Mascherano, who got the final touch for an own goal.

And 60 seconds later Stewart, who began last season on loan with Swindon, robbed none other than Spain star Sergio Busquets before playing in Origi to roll home number three.

Another substitute, Serbian midfielder Marko Grujic, grabbed a superb fourth with a looping header in stoppage time to cap a commanding Liverpool display.