Former World No. 1 Mats Wilander has claimed that Roger Federer's "level is lowering," as he explained how the Swiss Master's tactical approach has changed over the years.

"Now he decided that he cannot let the opponents take rhythm. Now his level is getting lower. While when he was at his best he was not worried for his opponents, now he has to," added Wilander in a recent interview.

This was not the first time Wilander has taken a dig at Federer this year. Following Federer's loss to Noval Djokovic in the Wimbledon final earlier this year, Wilander had slammed the 20-time Grand Slam winner for playing it safe.

Federer and Djokovic fought an epic five-set battle before the Serbian denied Federer a 21st major title by winning the final 7-6 (7-5), 1-6, 7-6 (7-4), 4-6, 13-12 (7-3). Federer had match points at 8-7 in the final set as he found himself 40-15 up on his own serve. However, he lost the next seven points as Djokovic turned the game around sensationally.

Wilander was quick enough to criticize Federer after the heart-breaking final. He said that the latter played a wrong game of tactics towards the end before he added that Federer had not improved tactically in the last few years.

Roger Federer
Roger Federer of Switzerland reacts during his match against Kei Nishikori of Japan during Day One of the Nitto ATP World Tour Finals at The O2 Arena in London, England, Nov. 11, 2018. Clive Brunskill/Getty Images

In a recent interview, Federer spoke about what makes fatherhood special. "It's just an amazing thing. You learn a lot about yourself but it's mostly about the love you have for your children and having something so unique with your wife is a beautiful thing. Mirka and I love every day with my kids. Four, it's been incredible. I never thought I would have that many kids by the way, but it's a lot of fun. I always wanted to have a big family at some point," the 38-year-old added.

Meanwhile, six-time Grand Slam winner Borris Becker heaped praise on Federer, calling him the most popular sportsperson across the globe. The former played suggested that if soccer star Lionel Messi was questioned in German or English, he wouldn't be able to answer, while Federer is fluent in English, German, and French. Becker also went on to say that Federer is easily more popular than the soccer and NBA stars.