Arne Slot says Ryan Gravenberch was taken off during Liverpool vs Manchester United because he twisted his ankle, with the Dutch midfielder set to be fully assessed in the coming days.
Liverpool will take on Eintracht Frankfurt in the Champions League on Wednesday, with Gravenberch a possible doubt for that fixture. The Reds then travel to Brentford next weekend.
Gravenberch was replaced by Curtis Jones with around half an hour to play in the Premier League clash. Cody Gakpo made it 1-1 around 15 minutes later before Harry Maguire's winner, powered home with his head after a Bruno Fernandes cross.
"I think we conceded a very sloppy second goal," Van Dijk said live on Sky Sports. "We worked so hard to get back into the game and we created great opportunities to score the winner.
"But if you concede a second goal like that, that is the disappointing part. If you look at the game as a whole, we were far too rushed.
"I think they were very patient. They didn't press us high but they didn't let us on the ball. We still created many opportunities to score, but the reality is that we lost."
"It makes it even harder if you are 1-0 down after one or two minutes," Slot added.
"If you told me that we would play against a low block and a team that plays so many long balls, that we would be able to create so many chances, I would think that we wouldn't lose the game, but we did, because we missed a lot [of shots].
"The few chances we conceded led to two goals and again, a set-piece is partly the reason why we lost the game.
"If you lose a game of football, especially after you have lost four, maybe I should not talk about that. No excuses. We have had more than enough chances to score a goal.
This article contains affiliate links, we will receive a commission on any sales we generate from it. Learn more
"I don't want to talk about (the referee). We had so many chances ourselves that we should have taken and we need to score more. If you are 1-1 and the game is completely there for you and you have to defend one set-piece, defend it better than we did.
"This is what we should focus on. If there is emotion in the game about decisions, that is something quite normal. Every manager has this but I should not talk about this."
There will be more to follow on this breaking news story and Liverpool.com will bring you the very latest updates, pictures and video as soon as possible.
Please check back regularly for updates on this developing story as they happen.
Follow @Liverpoolcom_ : The official Liverpool.com account for all the latest sports news as it happens in real time.
Follow us on Facebook or visit Liverpool.com homepage.