Liverpool manager Jurgen Klopp has admitted that he is concerned by the injury picked up by James Milner just a week before the new Premier League campaign.

The 30-year-old was withdrawn shortly before the half-time interval in the Reds' rampant 4-0 win over Barcelona at Wembley to be replaced by Alberto Moreno.

Milner, who retired from international football this week in order to focus on his club career, could now be doubtful for next week's trip to take on Arsenal at the Emirates Stadium.

Speaking to reporters, Klopp said: "[The injury] doesn't look too good. He picked up something on the heel; we're not too sure. But I'm happy with the result and a lot of parts of the game. We did well in most parts."

Milner featured 28 times for Liverpool in the Premier League last season, scoring five goals and setting up a further 11 for teammates.