Lacklustre Liverpool beat Midtjylland 2-0 on Tuesday to make it two wins out of two in the Champions League but their defensive problems mounted as Fabinho limped off injured.
The Premier League champions were toothless in the first half but finally clicked 10 minutes after the break when the impressive Trent Alexander-Arnold set up Diogo Jota for a tap-in.
A late penalty scored by substitute Mohamed Salah gave the scoreline unwarranted gloss.
The manager left his first-choice attack of Salah, Sadio Mane and Roberto Firmino on the bench against the Danes, giving his second string a chance to shine.
But Liverpool, lacking urgency and fluency at an empty Anfield, struggled to break down the hard-working visitors, who lost their Champions League opener to Atalanta 4-0.