Dejan Lovren is reportedly a major doubt for Liverpool's meeting with Leicester City next week after travelling to Germany in an effort to cure his persistent knee problem.
The 27-year-old has sat out the Reds' last two matches due to the troublesome issue, which also prevented him from taking part in the club's warm-weather training camp in Spain last weekend.
Jurgen Klopp expected the Croatia international to resume training this week, with an eye on making his return at the King Power Stadium in seven days' time, but The Telegraph claims that further specialist advice has now been sought.
Lovren, who has featured 20 times for Liverpool in the Premier League this season, is understood to have been carrying the knock for the majority of the campaign.
Klopp could once again turn to Lucas Leiva to partner Joel Matip in the heart of defence should Lovren miss out next week, while Ragnar Klavan is also available.