Liverpool could be left without midfielder Georginio Wijnaldum for their clash with Manchester United after he limped off an hour into the Netherlands' World Cup qualifying defeat to France on Monday night.
The 25-year-old earned his 32nd cap in starting the Group A clash in Amsterdam, but was forced off mid-way through the second-half clutching his hamstring.
United midfielder Paul Pogba's first-half strike proved the difference between the two teams as the Dutch slipped down to third in their group, three points behind both France and Sweden.
Though Wijnaldum left the pitch unassisted, the problem will no doubt have caused concern to manager Jürgen Klopp - who is already sweating on the fitness of a number of other regulars.
Adam Lallana is fighting a battle to be fit to face United at Anfield on Monday 17 October with Nathaniel Clyne and Dejan Lovren needing to shake off knocks in order to feature.
Klopp had been expected to make only minor changes for the visit of Jose Mourinho's men, but could now be forced into changing the make-up of his midfield with Lallana and Wijnaldum both significant doubts.
Reds hoping for positive Wijnaldum news
That would undoubtedly be a huge setback for the Reds, with the pair having been increasingly impressive alongside captain Jordan Henderson in recent games.
The fit-again Emre Can, who scored in a behind-closed-doors friendly win against Bradford City on Sunday, could be pushing for a start - although it is not yet known whether he will fill in at defensive midfield, where Henderson has shone in recent matches.
Summer signing Wijnaldum returns to Merseyside from international involvement on Tuesday, with the club's medical staff expected to determine the extent of his injury at Melwood.
Elsewhere in the international break on Monday, Estonia captain Ragnar Klavan couldn't prevent his nation losing 2-0 to Greece in the capital of Tallinn despite playing the full 90 minutes.
Divock Origi and Simon Mignolet were unused substitutes for the second time within four days as Belgium thrashed Gibraltar 6-0 at the Estadio Algarve in Portugal, with former Liverpool striker Christian Benteke scoring a hat-trick - his first coming after a record-breaking seven seconds.
Otherwise, young midfielder Ovie Ejaria netted his first ever international goal for England Under-20s as they left it late to beat the USA 2-0 in Rochdale for their third win from three in the Four Nations tournament.
Meanwhile on Saturday, Reds skipper Jordan Henderson will captain the England national team in their World Cup qualifying clash against Slovenia in Ljubljana.
Elsewhere Serbia midfielder Marko Grujic, Wales winger Harry Wilson and Scotland goalkeeper Ryan Fulton will all hope to feature for their respective Under-21s sides.