"I love what I see from Sebastian Korda, he's the first American in a long time that has top 3 potential" - Andy Roddick

Former World No. 1 Andy Roddick believes American sensation Sebastian Korda has made giant strides on the ATP Tour and should aim to finish the season inside the top 20.

Korda has tasted a lot of success this year. He won his maiden ATP title in Parma and backed it up by reaching the Wimbledon fourth round. The 21-year-old's strong results enabled him to break into the top 50 of the world rankings for the first time earlier this month.

Roddick, the last American to be ranked No. 1, said in a recent interview with Tennis Channel that Korda has been playing at a very high level and is capable of going further up the rankings.

"You are 45 [in the rankings], but you have done the bulk of your work in the last six months. You are going to shoot up further when the COVID-19 rankings readjust," Roddick said. "I think in the real-time rankings, he's somewhere in the top 20 and that's probably what he should shoot for by the end of the year."

Roddick went on to commend Korda on his strong work ethic, saying the 21-year-old "goes and tries to put up results every week".

The former US Open champion was also impressed by his compatriot's well-rounded game and ability to perform well on all surfaces. According to Roddick, Korda has the potential to break into the top three in the future.

"He's not satisfied. He goes and tries to put up the results every week, whether it's on clay in Europe, whether its indoors, a Challenger or a Tour event [...] and I love seeing that," Roddick said.

"He's a complete player. He can take the game to people, can switch directions off of both both sides. I love what I see from him and he's the first guy in a long time that I look at from the States and say that he's top 3, top 5 potential."

"Would love to see him open up his shoulders a little more" - Roddick's serving tips for Sebastian Korda

Roddick believes Korda could make some impovements on serve.

During the conversation with Tennis Channel, Roddick, who was renowned for his powerful serve, had a few words of advice for Sebastian Korda. The 2003 US Open champion believes serve is one area Korda still has room for improvement.

"I would love to see him, kind of, open up the shoulders a little bit more on the serve [...] and to be able to throw it at 125-130mph with consistency," said Roddick.

"We remember that match at Wimbledon against Karen Khachanov, where he was broken six times in a set. That's not going to happen in a year or two from now," he added.

Korda was set to take on Japan's Yoshihito Nishioka in the first round of the 2021 National Bank Open on Tuesday, but was forced to withdraw from the event due to a lower back injury. He is still scheduled to play in the upcoming Cincinnati Masters and US Open later this month.