World No. 1 Rafael Nadal admits retirement is approaching, however, he is not too worried about the prospect ahead of the Barcelona Open this week.

Nadal returned to competitive action as he won his first title of the year at the Monte-Carlo Masters on Sunday after defeating Kei Nishikori in straight sets during the final to retain the first of four clay titles he won last year.

The Spaniard notably near-dominated the entire clay-court season in 2017, winning a historic 10th French Open and only failing to win the Italian Open. He also went on to win the US Open and the China Open as he finished the year with a total of six titles — his best tally since 2013 — and ended the season as the top-ranked player in the world.

But with injuries marring his tennis participation since his withdrawal from the Paris Masters in late October, Nadal is simply hoping to enjoy his current success at the age of 31 and not worry about retirement, even if he acknowledges that it is closer than before.

"My true feeling is that these kind of things are not going to happen forever, so I just try to enjoy and to play with full passion and with full energy and concentration, full love for the sport for as long as I can," Nadal said, as per Tennis365. "I know the day to say goodbye is closer than 10 years ago. It’s something that I am not worried about, but it’s a real thing. So I’m just enjoying every day and trying to play with the best attitude possible, to keep being happy playing tennis."

Next up for Nadal is the Barcelona Open with his opening round match taking place against fellow Spaniard Roberto Carballes Baena on Wednesday. The 16-time Grand Slam winner has to retain his title in Barcelona along with his Madrid and French Open titles if he wants to remain atop the rankings.

But with Federer just 100 points behind him in the rankings, Nadal is not concerned about the battle with the Swiss legend as he reiterated his focus on being able to play tennis after previously featuring at the Australian Open in January where he withdrew in the quarterfinal stage.

"For me the extra motivation is just playing the tournaments that I am playing," Nadal explained. "Monte-Carlo, for me is like a love story and here, almost the same. My real motivation is just play, Monte-Carlo last week and now play Barcelona. That's a tournament that I have had a lot of success and I really feel the passion for playing."

Nadal faces a tough route to the final in Barcelona as he could face the likes of Nishikori, Novak Djokovic and David Goffin before a potential final with either Dominic Thiem or Grigor Dimitrov. However, the 31-year-old will still remain the favorite.