By Pravin Char

LONDON (Reuters) - Canada's Milos Raonic said John McEnroe had played a big role in improving his grasscourt game and match mentality after he overcame Sam Querrey to power into the Wimbledon semi-finals on Wednesday.

Raonic produced an irresistible display to beat American Querrey 6-4 7-5 5-7 6-4 in the quarter-finals and set up a clash with seven-times champion Roger Federer in the last four.

The influence of McEnroe, who joined his coaching team in the run-up to the tournament, was apparent as Raonic charged into the net behind his booming first serves and confounded Querrey with a succession of deft winning volleys.

"It was very clear, the things he believed I needed to do," sixth-seeded Raonic told reporters about McEnroe.

"We really focused on not passing up any opportunities to come forward, to always keep the pressure on my opponents, keep them guessing, making them feel uncomfortable."

Raonic said three-times Wimbledon champion McEnroe - who was commentating for TV on Federer's five-set match against Marin Cilic rather than watching his charge play - had also stressed the importance of having a positive attitude on court.

"He definitely keeps emphasizing demeanor on court, which I probably would not have put as one of the priorities," he said.

"I think it's about making sure you don't let yourself just quietly drift away in important moments - whether that's being more vocal, being more positive."

GUNS BLAZING

The 25-year-old came out all guns blazing against Querrey.

So great was his control of the first two sets that he lost just seven points on his serve during that period and faced no break points, in a display at times reminiscent of American Pete Sampras in his heyday.

"I've always looked up to Pete," he said. "He was definitely the best guy at keeping guys off balance. In important moments he made critical balls. I'm trying to implement that somewhat."

Querrey, for his part, was not able to produce the kind of scintillating form from the baseline that knocked world number one Novak Djokovic out of the tournament.

The ferociously whipped top-spin forehand that had served the American so well in previous matches misfired at critical times against Raonic.

The 28th seed raised his game to finally break the Canadian's serve in the third set and take the match into a fourth.

Raonic failed to reproduce the champagne tennis of the early stages, but nonetheless reasserted his dominance to reach his second Wimbledon semi-final.

Raonic said he was looking forward to playing Federer, and that his goal was to win the tournament.

"I have very clear objectives for myself," he said. "To achieve those things, you have to face off against the best players. I hope I can relish the opportunity."

He said it was helpful to have the advice of a past champion like McEnroe as he prepared for the match, but that ultimately it was down to him to produce the goods.

"At the end of the day, you got to step out there and find a way to win, try to win that last point."

(Editing by Ken Ferris and Ed Osmond)