Liverpool manager Jurgen Klopp has suffered yet another untimely injury scare ahead of Saturday lunchtime's Premier League Merseyside derby against Everton at Anfield.
The Reds will seek to snap a two-game winless run in the top flight when they resume domestic duties this weekend, having taken just one point from six before the October international break.
An infuriating 2-1 loss at Tottenham Hotspur - where Luis Diaz had a goal wrongly chalked off - preceded a 2-2 draw with Brighton & Hove Albion, where Lewis Dunk bagged a late equaliser for the Seagulls.
Liverpool's recent patchy spell has seen Klopp's side drop to fourth place in the Premier League standings, three points below leaders Tottenham Hotspur and second-placed Arsenal.
The Reds' medical team have already been dealing with an influx of players into the treatment room since the season started, and the Anfield giants must now cope with a fresh concern to 17-year-old winger Doak.
The former Celtic youngster was called up to the Scotland Under-21 squad for their Euros qualifiers against Hungary and Malta, starting and scoring from the penalty spot in a 3-1 win over the former last Friday.
However, Doak was then withdrawn just after the hour mark in that affair, and he was subsequently ruled out of Scotland's 2-1 win over Malta on Tuesday with that unspecified concern.
The Liverpool Echo states that the Reds are still none the wiser when it comes to the severity of Doak's problem, but the 2005-born starlet has now emerged as a doubt for the visit of Everton.
Barring a late fitness problem for Mohamed Salah, Doak would have only been on the bench for the derby, but the teenager has already made quite the impression during his earliest days at senior level.
Doak has already made eight competitive appearances for Klopp's side, including starts in the Europa League and EFL Cup this season, prior to which he played in five pre-season friendlies and scored in a 4-0 thrashing of Leicester City.
Alongside the stricken Scotsman, Liverpool are guaranteed to remain without Thiago Alcantara (hip) and Caoimhin Kelleher (knee) this weekend, while Andy Robertson is expected to miss out too.
The 29-year-old suffered a suspected dislocated shoulder in Scotland's defeat to Spain last week, and while an official diagnosis has not yet been released, Kostas Tsimikas is set to deputise on the back of signing a new contract at Anfield.
In addition, Curtis Jones must serve the second of a three-game domestic ban, while Stefan Bajcetic is touch-and-go owing to the calf injury which has kept him out of the Reds' last four matches.
However, Diogo Jota will return from a one-game suspension to bolster Liverpool's attack, and there is also hope that Cody Gakpo's knee problem could heal in time for the Dutchman to be involved. body check tags ::