England coach Stuart Lancaster has told Saracens wing Chris Ashton that he has to improve his tackling technique.
He is suspended for Saturday's game against Fiji after a dangerous tackle on Northampton's Vasily Artemyev.
Lancaster told BBC Sport: "He needs to improve his style of tackle because clearly it's been an issue.
"It's something we've spoken to him about, in terms of his tackle technique but also making sure he controls his competitive nature."
Including the retrospective action for the Artemyev incident, which saw his technique criticised by the Rugby Football Union disciplinary officer, Ashton has received three yellow cards this season.
The 25-year-old was also suspended for four weeks last season for unsportsmanlike behaviour after pulling the hair of Leicester wing Alesana Tuilagi.
Lancaster said England had been trying to iron out Ashton's faults during training.
"We'll work on it this week because he's in camp with us," said the England boss.
"It's not something which can't be solved pretty quickly and hopefully it won't be a repeat occurrence."
The England coach is confident that lock Tom Palmer and prop Joe Marler will be available after respective calf and hamstring problems.
Lancaster, who will name his team for the Fiji match on Thursday, has also played down the chances of Gloucester fly-half Freddie Burns winning his first cap this weekend.
Burns, 22, has been in outstanding form for his club this season and was called into the squad on Sunday as injury cover.
"For a fly-half to come into any team and take control of it without really knowing the structures and systems you're playing with, it's very difficult," said Lancaster.
"Also, I do think Toby Flood has played extremely well recently and Owen Farrell the same. So it's great that we've got that quality in that key position."