Milos Raonicof Canada returns to Roger Federer of Switzerland during their semi-final match of the Wimbledon Championships at the All England Lawn Tennis Club, in London, Britain, 04 July 2014. ( / )

Twenty-three-year-old Milos Raonic reached the French Open quarterfinals, though clay isn’t his best surface. Then he charged onto Centre Court for Wimbledon semifinal against Roger Federer, though grass isn’t his thing either.

So you’d think, as Raonic arrives in Washington this week as the second seed in the Citi Open and seventh-ranked player in the world, Raonic would be feeling pretty happy. You’d be wrong.

“Of all the rankings climbs I’ve made that have been significant to me, it’s probably the one I enjoyed the least because I could’ve done much better in that situation. And would’ve wanted to do better in that situation,” Raonic said of the straight-set loss to Federer. “To this point, it’s been a lot of frustration, anger, and disappointment . . . it’s been transformed into a lot of energy to do better.”

The Canadian said he’s carrying both momentum and motivation into the hard court series, where he says he “feels most comfortable.”

His blistering serve rockets around the hard courts, even faster in the heat, which he calls “the best thing for my game.” Raonic says he understands how to use that serve and other big swings better than ever.

“I have more belief and understanding of the damage I can make,” he said. “That I can make guys feel uncomfortable. Whether No. 1 in the world or No. 50, I don’t think anyone feels comfortable playing me, and I want to use that to my advantage.”

That confidence has Raonic believing there’s room for him at the seemingly impenetrable top of the ATP rankings, that “the biggest barrier is the threshold Rafa and Novak have on the one-two spots.”

“I think the rest of the spots in the top five, this year specifically, are up for grabs,” Raonic said.

If he wants to bolster his résumé for one of those top spots with a Citi Open title, Raonic will need to get past Tomas Berdych, the tournament’s top-seeded player and No. 5 in the ATP rankings. Berdych says he’s less certain the top four spots — Djokovic, Nadal, Federer, and 2014 Australian Open champion Stan Wawrinka — are imminently seizable.

“It’s really tough to break in; it’s hard to explain with a better word,” Berdych said. “. . . I would basically say you need to win a slam to get there because the other guy is going to have at least one. If you want to be part of that, you really need to get that one to get into the top four or top three.”