Roger Federer
Roger Federer is skipping the clay-court season again. Pictured: Mar 24, 2018; Key Biscayne, FL, USA; Roger Federer of Switzerland hits a backhand against Thanasi Kokkinakis of Australia (not pictured) on day five of the Miami Open at the Tennis Center at Crandon Park. Geoff Burke-USA TODAY Sports

Roger Federer's selective approach in choosing which tournaments he plays in is unfair according to 1970 French Open champion and Mutua Madrid Open owner Ion Tiriac.

Federer returned from a long injury layoff in 2017 to win the Australian Open in what was his first Grand Slam victory since 2012. The 36-year-old continued to defy his age afterward by winning titles at Indian Wells and the Miami Open.

However, following his "Sunshine Double" achievement, he made the controversial decision of skipping the entire clay swing in a bid to maintain his fitness ahead of his much-preferred grass-court season.

The decision did not go down well with everyone, but it paid dividends in the end as Federer won more titles at the Halle Open, as well as a record-breaking eighth Wimbledon crown, before ending the year with victories at the Basel Open and Shanghai Masters.

The Swiss legend's career resurgence continued in 2018 as he won the Australian Open for the second year running, along with becoming the oldest world number one in tennis history, as he went on to win the Rotterdam Open.

But despite hints that he might feature this time around, the now number 2 ranked Federer made the decision to once again skip the entire clay-court season following losses at Indian Wells and the Miami Open last month. Tiriac was not pleased with the 20-time Grand Slam champion's behavior.

"Roger Federer is certainly the best player ever, but he does not behave correctly," Tiriac was quoted as saying on the Express. "I do not think his approach is fair. Lewis Hamilton does not just say no more after five Grands Prix in Formula One, because he does not feel like it."

It is not the first time Tiriac has spoken about the issue — he criticized Federer last year as well when the Basel native decided to skip his event, stating the Association of Tennis Professionals (ATP) events could not count on him anymore.

"I expected to see Federer in Monte Carlo, Madrid and Rome," Tiriac said in May 2017. "Through his career he always did his job but now it's different. He plays sometimes and we can't count on him anymore."

"Federer is a great champion. He is good for tennis but it's not positive for the [ATP] Tour to play so less. In tennis there aren't only major events, but also nine Masters 1000s that lasts 12 weeks in total. 80% of the money comes just from these events."

Federer is expected to return to action at the Mercedes Cup in Stuttgart, Germany, which takes place from June 11-17. Last year at the event, he was notably eliminated in a round of 16 upset against Tommy Haas who triumphed in three sets.