Liverpool boss Andoni Iraola says he was angry about being prevented from making a triple substitution sooner during Saturday's 2-2 Premier League draw against Nottingham Forest.

With the game level at 1-1 during the second half at Anfield, the Basque wanted to bring on Ryan Gravenberch, Kostas Tsimikas and Rio Ngumoha.

However, despite the ball going out of play three times, the players were left waiting on the sideline as fourth official Tim Robinson had problems with the board.

To add to Liverpool's frustrations, the third time the ball went out, instead of play stopping for the changes, Forest took a quick throw-in from which they won a penalty to retake the lead.

Forest wing-back Neco Williams darted in behind the Liverpool backline and was caught by goalkeeper Alisson as he lifted a shot goalwards.

When it drifted wide, referee Samuel Barrott blew his whistle and pointed to the spot.

"With the penalty, the situation has already finished when the contact appears. And it's not an aggressive contact," Iraola told BBC Match of the Day.

"But more than this we complained about the subs. We had to wait about three minutes.

"He was having an issue with the board, I don't know if it was not working, but we definitely wanted to do the subs the last two or three stoppages before the goal.

"It wasn't just that reason but everything helps."

Speaking to TNT Sports, he added: "A professional fourth official cannot take three minutes. We'd already given him the subs two or three minutes before.

"I was already angry because in the previous stoppage we couldn't make the subs and then before throw-in I thought we could do it.

"I don't know, they will have to explain it. But it has taken ages."