The opening 45 minutes at Old Trafford was particularly notable due to the amount of substitutions required, with Ole Gunnar Solskjaer forced to make all three of his.
Ander Herrera and Juan Mata both came off, as did Mata’s replacement Jesse Lingard, while Firmino had to make away as he twisted his ankle on the turf in Manchester.
His place was taken by Daniel Sturridge, who unsurprisingly struggled after playing just 228 minutes in the past three months, as Liverpool were held in another tough clash.
With Watford to visit Anfield on Wednesday before the Merseyside derby at Goodison Park next Sunday, Firmino’s fitness will be a big concern for Klopp.
And the Mail‘s Dominic King took to Twitter after the game to reveal that the 27-year-old had left Old Trafford on crutches, though he added “his foot is not in a [protective] boot.”
Speaking to Sky Sports, the manager said “hopefully it’s not too serious,” but that he “didn’t know in the moment.”
Klopp went on to label Firmino’s withdrawal as a “catastrophe for us,” and it could be even worse if he misses any of Liverpool’s upcoming games—which may be likely, with ligament damage possible.
Liverpool are likely to provide a further update on Firmino’s injury in the near future.