WALES head coach Warren Gatland believes England will have a emotional "time-bomb" in their front row in the red-hot Cardiff atmosphere of today's Six Nations showdown.

Gatland was tighthead Kyle Sinckler's boss when the British and Irish Lions drew with world champions New Zealand in 2017.

The Wales boss is full of admiration for the prop, but says the Harlequin has a short fuse.

Sinckler has twice been involved in incidents during this season's tournament.

In England's opener against Ireland he became embroiled in an exchange with flanker Peter O'Mahony off the pitch, and in the France game eight days later he was reminded of "rugby's values" by match referee Nigel Owens after slapping Les Bleus forward Arthur Iturria on the head.

Speaking last week about the Iturria incident, Sinckler said: "I don't condone what I did, but they didn't show the full replay of what actually conspired. I didn't just smack him on the head. There was stuff that happened before.

"I am not perfect, and I have learnt from it."

Gatland said: "I think the thing with Kyle, there is no doubt he's a very good player in terms of his carrying, scrummaging and work rate.

"There is a challenge sometimes with his temperament. He's aware of it. Other players are aware of it. We've already seen in the Six Nations that he has been involved in a couple of incidents.

"Hopefully, we don't get dragged into that. Emotionally, he can be a bit of a time-bomb. I am not saying anything that people aren't aware of.

"Look, we won't be going out there trying to antagonise him, because that's not in our make-up. We will just go out there and play.

"Hopefully, he goes out and has a good game and is able to keep his emotions in control, because that's a big challenge for him."

Gatland has also underlined the need for his players to remain disciplined.

"There is no doubt it's going to be incredibly physical with a lot of passion involved," he added. "Discipline is going to be paramount.

"I want my players to bring that physicality and be emotional, but I don't want them going over the top, losing their edge or getting involved in foul play.

"We want to play tough and hard, bring as much physicality as we can, but playing to the laws of the game."