Steve Bruce confirmed that Matt Ritchie would miss the next two months after suffering ankle ligament damage against Leicester City.
Bruce saw three players go off injured on Wednesday but Jetro Willems and Emil Krafth have been back in training ahead of the match against Watford.
Bruce spoke on other injuries: "I have doubts on Emil Krafth, Jetro too and Miguel is a bit of a problem.
"Joelinton should be OK."
Ritchie has started every game under Bruce this season and with Willems, not 100% match fit it leaves Bruce with a selection headache.
Major blow to a crucial player
The Scotland international has been an ever-present in the Newcastle side since signing from Bournemouth in 2016 when the Magpies dropped into the Championship.
Ritchie has been deployed as a left wing-back under Bruce just like he was at the end of last season and has performed exceptionally well.
Which makes it a bigger blow for Bruce as he must decide to stick with his three at the back formation or switch to a flat back four.
It is not just his versatility the Magpies will miss as he is the best set-piece taker at the club as well as the designated penalty taker.
A major void left on the pitch
However, it is his vocal presence on the pitch as he constantly demands more of his teammates and guides the defence and midfield during the 90 minutes.
Bruce spoke in his press conference:
"It could have been worse, six months, but it was one of those horror challenges.
"I understand that the lad has apologised.
"What was disappointing was the ref who was very close to it."
Understandably Ritchie was not happy with the challenge and was even more annoyed to learn the length of time he would spend on the sidelines.
Which shows the type of character he is on and off the pitch and what he brings to the team and especially inside the dressing room during difficult times.
Bruce added: "Matt is angry but he will get over it and start working."