Roger Federer
Roger Federer last featured at the Miami Open in March. Pictured: March 24, 2018; Key Biscayne, Florida, Roger Federer of Switzerland hits a backhand against Thanasi Kokkinakis of Australia (not pictured) on day five of the Miami Open at Tennis Center at Crandon Park. Geoff Burke-USA TODAY Sports

Roger Federer's schedule for the upcoming grass-court season is revealed after an update on his official website.

The Swiss legend is enjoying a career renaissance that dates back to the beginning of 2017 as he started this year off by retaining the Australian Open in January when he defeated Marin Cilic over five sets in the final.

Federer then created tennis history when he became the oldest No. 1 of all time en route to winning the Rotterdam Open in February in what was his ninth overall title since returning from an injury last year.

However, he suffered two consecutive defeats for the first time since 2014 when he lost to Juan Martin del Potro in the final of the BNP Paribas Open in Indian Wells, California, before losing his opening round match at the Miami Open to Australia's Thanasi Kokkinakis in March.

As a result, Federer also lost his place at the top of the rankings to Rafael Nadal as he later announced he would once again skip the entire clay-court season like he did last year, despite previously hinting at participating in it.

"I decided not to play the clay season … I am trying to figure things out now, I have some time," Federer said after his Miami Open exit. "I'm a positive thinker, every match is another opportunity. You take a break, get away from it all, and get back to practice court and work."

Having been a month since he last played, the 36-year-old is now confirmed to return for the Halle Open which takes place from June 18-25 before embarking on a potential ninth Wimbledon crown when he participates at SW19 from July 2-15.

Federer won both those events last year and will be defending a total of 2,500 points as he hopes to surpass Nadal once again in the rankings and become No. 1 for the fifth time in his long career.

However, there is interestingly no mention of the Mercedes Cup in Stuttgart as of now, which is scheduled to take place from June 9-17. Federer notably lost his opening round match last year in Stuttgart when he was defeated in three sets by Tommy Haas.

The entry list for the event will be released next week and unless Federer makes a swift decision on his participation, he will need a wild card if he does go on to enter the grass-court season opener.

Meanwhile, Nadal is through to the quarterfinals of the Barcelona Open after a 6-1, 6-3 win over Guillermo Garcia-Lopez on Thursday. The Spaniard also extended his current clay record to 40 consecutive sets won and 16 matches in the process.

Nadal will next face Martin Klizan — who notably eliminated Novak Djokovic — as the 16-time Grand Slam champion must retain his Barcelona title if he wishes to remain No. 1 in the rankings above Federer.