Roger Federer might be just two wins away from becoming the oldest world number one in tennis history, but the 20-time grand slam champion is already looking ahead to his next challenge.

A semi-final finish at this week's Rotterdam Open will be enough to replace Rafael Nadal atop of the ATP rankings, yet the 36-year-old still is wasting little time identifying new targets.

Federer has outlined ambitions of reaching 100 career singles titles on the men's tour, something only one other player has achieved. The Swiss is currently on 96 after winning the Australian Open and aims to join American Jimmy Connors, who leads the way on 109.

"I like to win titles being on a Tour," he said, according to Sporting News. "Being at a hundred would be an extremely cool number.

"Here I am at 96. World number one would be very special. Good matches, good feelings, good vibes. You need to have goals when you want to be successful."

He could take a step towards that landmark this week if he is able to prevail in Rotterdam. Federer began his campaign with a routine win over Ruben Bemelmans and faces Philipp Kohlschreiber on Thursday (15 February) for a place in the quarter-finals.

Returning to world number one for the first time since October 2012 would see Federer, who has already spent 302 weeks as the main man in the sport, add further to an already glittering CV.

But the potentially historic moment has not captured the imagination of everyone in the Federer household, with the right-hander admitting his twin daughters are oblivious to the development.

"The girls might be excited," he said of eight-year-old Myla and Charlene. "I don't even know if they know I can become number one this week.

"It's for my team. It is more for everyone who helped me come back. Coaches go way back, it would be a massive achievement for them."

Roger Federer
Federer is eyeing a return to the top of men's tennis. Getty Images