Liverpool manager Jurgen Klopp believes a proposal to introduce blue cards and sin bins to football does not “sound like a fantastic idea” initially.

The PA news agency understands that blue cards will be shown to players sin-binned in new trials to try and improve participant behaviour.

It is understood that the initial trial phase will not feature top-level competitions to avoid players being in events with different rules concurrently.

PA understands that plans to publish details of these trials have been delayed until next month, but Klopp believes a blue card could present “more opportunities to fail”.

He told a press conference: “I think everything what the actual situation shows is we should keep it as simple as somehow possible, for the referees as well.

“It’s a difficult job, often quite emotional when we speak about it more so because it’s after the game, and I think the introduction of a blue card would just give more opportunities to fail as well because the discussion will be: ‘It was a blue card, should it have been a yellow card, now it’s 10 minutes off, in the good old times it would have been a red card or only a yellow’.

“These kind of things just make it more complicated. If they want to test it I have no problem with testing if that’s the first step to agreeing or it already being sure it will happen – I don’t know that.

“It doesn’t sound like a fantastic idea in the first moment but actually I can’t remember the last fantastic idea (which) came from these guys, if they ever had one. I am 56 and, pah, never.”

Tottenham manager Ange Postecoglou also remained unconvinced by the proposals, adding his “biggest issue” in football is VAR.

“I don’t think people will be surprised by my thoughts on it. I struggle to understand this urgency all of a sudden to bring in new things,” he said.

“I don’t know if there’s that much wrong with the game as I see it. My biggest issue with the game right now is that VAR has changed the experience, whether you’re a player, a manager or a supporter or whatever you are I think it’s changed the experience of football.

“I assume that’s a means to an end, that the introduction of technology is going to get us to a better place. I remain to be convinced about that.

“Beyond that, I don’t know why a different colour card is going to make any difference. I struggle with this whole taking from other sports.”

Arsenal boss Mikel Arteta hopes that the proposals would be “tested very well” if introduced.

“I don’t know when we’re going to get there,” he said.

“I think we’ve got a lot going on with decisions, with technology, with what is coming. I don’t know if we are ready for that yet.

“Who knows (if it is a good idea). Hopefully it’s going to be tested very well before they introduce it at this level.”

Newcastle manager Eddie Howe admitted he was “not a big fan” of the new proposals.

He said: “I’m not a big fan, to be honest. I think that’s what yellow cards are for. I think the current system works well, it’s just got to be applied right.

“I think adding a blue card would just add more confusion, in my opinion, so I’m against it.

“I think (sin bins) would change it a lot, but again not, for me, in a good way because I think it will make it very bitty, more stop-start.

“I fear for the players who would have to go off for 10 minutes and then re-find the rhythm of a Premier League game after 10 minutes out, I’m just not sure it works, personally.”

Wolves boss Gary O’Neil believes blue cards could “damage” the stadium experience.

“I haven’t looked into it too much, it would damage the in-stadium experience, it would change the game drastically, to have to spend 10 minutes down to 10 men,” he said.