Liverpool suffered an injury scare less than a week before the start of the Premier League season after Andy Robertson hobbled off in the friendly draw against Athletic Bilbao at Anfield.
The Scotland left-back, who started every league match last season, had to be helped off the pitch by two of the club's medical team shortly before half-time in the 1-1 draw after appearing to fall awkwardly and injure an ankle attempting to stop a cross by Alex Berenguer.
Only seven outfield players played more Premier League minutes than Robertson last season while his likely deputy, Kostas Tsimikas, managed just six minutes in his maiden campaign for the Reds.
"We don't know how serious it is. It was pretty painful and that is why Andy went off," said boss Jurgen Klopp, whose side kick-off their season at Norwich next Saturday evening.
"He got the ball on the front of his foot, twisted his ankle. The pain settled already but we cannot say without further assessment.
"He needs to get a scan and then we will know more."
Robertson tweeted on Sunday evening: "Your support today was amazing! Thank you for all your messages, I'm positive but let's see what tomorrow brings!"
On the plus side, Virgil Van Dijk continued his comeback by playing 71 minutes against the LaLiga side, the most he has managed since an anterior cruciate knee ligament injury in October, alongside Joel Matip, whose season was also prematurely ended in January by an ankle problem.
The Holland captain cruised through the game, launched a number of his trademark long crossfield passes out from the back – one early one dropping right onto the toes of Mohamed Salah – and could have scored a couple of headers from corners.
All of which will have raised hopes he could yet be included for the trip to Carrow Road.
The team Klopp named, with Alisson in goal, a back four of Trent Alexander-Arnold, Van Dijk, Matip and Robertson, a midfield of James Milner, Naby Keita and Harvey Elliott – the 18-year-old impressing again in pre-season – and a front three of Salah, Diogo Jota and Sadio Mane could well be close to that which lines up against Norwich, Robertson's injury notwithstanding.
Fabinho, who is set to play in Monday's Anfield friendly against Osasuna along with first pre-season outings for Thiago Alcantara and Jordan Henderson, is likely to come in for Elliott next weekend but the Reds boss may have given an early indication of his thinking.
Jota struck in only the 13th minute after Keita and Mane had combined to set him up for an angled drive, but despite creating a host of chances Liverpool were pegged back by Berenguer's goal just after half-time.
"For 55 minutes we saw an absolutely top game from my team with the boys obviously inspired by the 42,000 people in the stands," added Klopp.
"I was more than pleased; if Robbo's injury had not happened I would have been over the moon."
