Liverpool defender Virgil van Dijk has questioned the referee's decision to not hand Tottenham Hotspur's Lucas Bergvall a second yellow card before the 18-year-old scored the winning goal in the Carabao Cup semifinal between the sides.

Stuart Attwell, the official in charge of the game, had earlier booked Bergvall for a foul on Luis Díaz and played advantage after another late tackle from the Swede on Kostas Tsimikas.

As Liverpool's attack petered out, Attwell did not stop play to show a yellow card to Bergvall and moments later the teenager slotted past Alisson after fine work from Dominic Solanke while Tsimikas was off the pitch receiving treatment.

"It was quite obvious there was gonna be a second yellow," Van Dijk told Sky Sports after the game.

"It was pretty clear, and then a minute later he scores the winner. Listen, it is what it is. [The referee] made a mistake in my opinion and I told him that. He thinks he didn't. It was quite obvious and everyone on the sideline knew it.

"There's a linesman there, there's a fourth official, there's VAR ... and he doesn't get a second yellow. I'm not saying this is the reason we lost, but it was a big moment in the game."

The Netherlands stalwart did add that Attwell's call wasn't the only reason Liverpool will head to Anfield to play the second leg facing a deficit.

"We played against an intense team with good attacking players who keep running and make it difficult," he said. "We created opportunities -- not really clear-cut chances in my opinion, but enough that we could have scored.

"At times we could have done better. That's part of football. At times we played through them nicely, but they were able to defend much better than when we were here a couple of weeks ago."

Arne Slot echoed Van Dijk's comments, saying: "The decision he [the referee] made had a lot of impact on the result tonight."

The second leg at Anfield is scheduled for Feb. 6. Liverpool play League Two team Accrington Stanley in the FA Cup third round on Saturday, while Spurs travel to National League side Tamworth.