The Lionesses star had a nasty clash of heads with Belgium's Jassina Blom on Tuesday night.
The pair collided while ducking to head the ball, resulting in Greenwood instantly hitting the deck.
A stretcher was promptly taken onto the pitch and there was a long delay before Greenwood was taken off the pitch.
Jess Carter was then brought on to replace her.
Meanwhile, Blom also received medical treatment and had a bandage put on her injury.
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There were 14 minutes added on at the end of the first half as a result.
Greenwood also suffered a head injury at the 2023 World Cup during the 1-0 loss to Spain in the final.
She was clattered in the second half during an aerial clash with Spain winger Salma Paralluelo, with Greenwood appearing to take a knee to the face.
Despite getting bandaged up and battling on in that game, she sported a large cut under her eyebrow and bruising on the Lionesses' flight back from Australia.
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The Lionesses had found themselves 1-0 down against Belgium after just nine minutes after Laura De Neve found the net.
But soon after Greenwood went off, Sarina Wiegman's side found an equaliser, with veteran star Lucy Bronze heading home Chloe Kelly's free kick.