Gatland, who picked Sinckler for all three Tests during the 2017 Lions tour to New Zealand, believes there is a “challenge with his temperament…other players are aware of” but has denied there is a plan to take advantage of any vulnerability during the crucial Six Nations clash at the Principality Stadium.
The 25-year-old prop has already served a seven-week ban for making contact with the eye area of an opponent on club duty, while in the win over France a fortnight ago he slapped France flanker Arthur Iturria on the top of his head, prompting a reminder of rugby’s values from referee Nigel Owens.
Sinckler is also an accomplished sledger who can often be heard directing verbal darts at the opposition. Against Ireland on February 2 he was embroiled in a spat with Peter O’Mahony.
England attack coach Scott Wisemantel has cautioned against trying to wind him up.
“If they target him then they’re leaving 14 other blokes to do their jobs, so good luck,” Wisemantel said.
“We saw in the Australia game during the autumn that he has a quick wit and can refocus very quickly. It’s probably Warren trying to stir the pot a bit.
“On the edge is the way he plays the game. Do you really want to take that away from someone? I don’t think so. He knows how to control himself and I don’t think it’s an issue at all.”
Courtney Lawes admits Sinckler treads a fine line at times but views his aggression as an important rallying point for England’s pack.
“Kyle’s awesome,” Lawes said. “He is great and he brings great energy and he pushes it to the limit and you need players like that in the team.
“It inspires the players around him and it makes you want to get with him. That makes him a great leader in that sense.”
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Jack Nowell has been restored to the right wing in the injury-enforced absence of Chris Ashton. Jonny May, the Six Nations’ leading try scorer who has flourished since Wisemantel was first appointed in June, starts on the opposite flank.
“They are pretty diverse players,” Wisemantel said. “We periodise Jonny’s week as the Ferrari.
“So the Ferrari gets put in the garage, we put the covers on the Ferrari and give it a good grease and oil change.
“That’s how we periodise Jonny’s week and it gives him a really good visual for his week. He is extremely detailed with his preparation.
“The aerial battles are where he’s improved. He has worked really hard on them and he has become the king of the air.
“With Jack, you get work rate, you get energy. He just loves being on the pitch. He’s got unbelievable footwork, he would beat you in a phone box. He has a high work rate and really good gas out of the blocks.
“They are very different characters but the one thing they both bring is lots of energy.
“They both love it when they are on the pitch but in the lead-up, they are totally different. They come together and in games.”
Watch: England head coach Eddie Jones speaks to RugbyPass about Wales game
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