This time it was Anthony Gordon who limped off early in the second half to add to their growing issues.
Gordon was the subject of a nasty challenge in the opening minutes of the game from Moises Caicedo, but he managed to play on for the rest of the half.
It is unclear if that tackle caused him an issue in the second half, but it was not immediately evident what had caused the problem.
Gordon was replaced by Matt Ritchie, with the Magpies leading 1-0 at the time.
The new blow comes ahead of a manic schedule of matches for Newcastle.
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They travel to Luton on Saturday before facing Nottingham Forest at home on Boxing Day.
Howe's side then face a tricky visit to Anfield on January 1.
The Magpies already have Nick Pope out for a significant period of time, while the likes of Harvey Barnes and Jacob Murphy have been long-term absentees.
Nick Pope - dislocated shoulder
Jacob Murphy - dislocated shoulder
Fabian Schar - hamstring
Joelinton - hamstring
Matt Targett - hamstring
Alexander Isak - groin
Joe Willock - Achilles
Harvey Barnes - toe
Elliot Anderson - back
Javier Manquillo - groin