Arne Slot welcomed an emphatic end to Liverpool’s losing run but fears he could be without Alexander Isak for several weeks after the British record signing suffered a groin problem against Eintracht Frankfurt.

Liverpool produced a 5-1 rout in Germany with Slot’s call for set-piece improvement answered by two goals from corners by Virgil van Dijk and Ibrahima Konaté. The win ended a sequence of four successive defeats for the Premier League champions but Isak had to be withdrawn after 45 minutes of his second start in four days. Slot believes the workload may have been too much for the striker, who missed most of pre-season at Newcastle in his attempt to force a £125m move to Liverpool.

Jeremie Frimpong is also facing another spell on the sidelines after sustaining his second hamstring injury of the season.

Slot said of Isak: “Let’s hope it’s not that bad, but he had to go off because he felt his groin. Many people wanted me to play him more and we had to find the balance and unfortunately today that balance didn’t work out for us perfectly. But let’s hope for the best. When he came to the club, he had hardly...