Old dudes rule tennis right now. Seven players in the ATP top 10 are 28 or older. Three of them — No. 2 Roger Federer, No. 4 Stan Wawrinka and No. 9 David Ferrer — are at least 30.

John Isner, an All-American while at the University of Georgia and a new member of the 30-year club, is confident against any fellow tennis veteran — and everybody else.

“I don’t really have any performance goals for myself, but I know I can beat anyone,” Isner said Wednesday at the BB&T Atlanta Open, where he’ll go for a third consecutive title Thursday.

When told about Isner’s comment, his coach, Justin Gimelstob smiled.

“I’ve always believed that,” Gimelstob said. “I think John has proven that if he plays his best he’s capable of beating everyone, if he plays the right style. He’s got huge weapons, and he’s incredibly disruptive to play against.”

Isner, America’s top-ranked man at No. 19, turned pro in 2007 and has been the country’s best hope for a Grand Slam title since Andy Roddick retired and Mardy Fish left tennis. He hasn’t advanced past a Grand Slam quarterfinal, though, and most recently lost in the round of 32 at Wimbledon to No. 9 Marin Cilic.

He cracked the top 10 after beating No. 1 Novak Djokovic at the BNP Paribas Open in Indian Wells in March 2012. He’s spent 20 weeks in the top 10 since then, but not since early May 2014.

“The potential for the best tennis is definitely ahead of him,” Gimelstob said. “I believe he’s improving, that he’s the best tennis player he’s ever been.”

Isner is 12-38 against the current top 10 and 2-7 this year. He picked up those two wins at the Miami Open, topping then-No. 6 Milos Raonic and No. 5 Kei Nishikori in consecutive matches and beating then-No. 11 Gregor Dimitrov in straight sets before that.

The 2-7 mark could easily be 5-4 or 6-3, though. Nine of his 16 dropped sets in the seven losses came on tiebreakers.

“Those guys are — you’re talking about the .00001 percent of greatness and excellence, and the challenge for John is to keep inching closer and closer,” Gimelstob said. “Keep moving the margins. And he’s played some great tennis. He’s lost some close matches; he’s won some close matches. That’s inherently the nature of his style, but I know in my heart that if he sticks with it that some of those matches will go his way. And with that comes momentum and confidence and more of those matches will go his way.”

Isner boasts nine ATP tour wins — all ATP 250s — and has two titles every year since 2011. He hasn’t won an event yet in 2015.

He’s finished second in nine other tournaments, including two ATP 1000s: Cincinnati in 2013 and Indian Wells in 2012. He beat No. 1 Novak Djokovic to make both those finals.

“I’ve beaten No. 1 players in the world. I’ve won big tournaments. I’ve gotten to the finals in big tournaments,” Isner said. “I know I’m a threat no matter who I’m playing against.”

Isner opens his play at the Atlanta Open against Radek Stepanek of the Czech Republic on Thursday evening at Atlantic Station.