Hamstring. No point in burying the lede; Liverpool have suffered their second hamstring injury of the season, two and a half weeks in. Philippe Coutinho follows in the limping footprints of his compatriot, Lucas Leiva, and, after having sat out the Reds' midweek hammering of Burton Albion, is now racing to be ready for Saturday's trip to White Heart Lane.
A hamstring injury in isolation is hardly a disaster, but given Liverpool's history with the crucial muscle cluster under Klopp - the squad suffered sixteen separate hamstring strains after the German's arrival last season - it would be easy to see this injury as more of a symptom of an underlying issue rather than a one-off.
The good news is that it's not a tear or a strain, but merely some stiffness. Nonetheless, Coutinho's involvement is going to be a matchday decision.
"The muscle was a little stiff, He felt something so we didn’t want to take a risk (against Burton).
"We left him out of training until now. We have to make a decision on Friday with what we can do with him.
"It is not a situation to take any risk. We have to talk to the player.
"From the medical side, it is not a big issue, but it was big enough to leave him out of the squad for Burton."
While Klopp is - perhaps rightly - downplaying the severity of the injury, the loss of one of the team's primary creators alongside promising goal scorer Divock Origi and starting defensive midfielder Emre Can undoubtedly leaves the squad in a weakened position ahead of what is likely going to be a challenging fixture against a high-intensity side that looked to be finding their feet last week after an uneven season opener.
With Lucas Leiva still recovering from his own hamstring injury, there is a strong chance that former Tottenham right-back reject Kevin Stewart will get a start against his old club, particularly if Klopp decides that the midfield configuration of the past three games has been more porous than he'd like.
Or perhaps they'll all shake it off in time for Saturday and we'll start our best eleven. Right?