Former No. 1 Marat Safin continued to fire shots at the younger players in tennis for allowing Roger Federer and Rafael Nadal to remain at the top of the rankings.

The major talking point of 2017 was the resurgence of Federer and Nadal, both of whom ended the year in the top two of the ATP rankings, shared the four Grand Slams, and won a combined 13 titles.

But with the absence of Novak Djokovic and Andy Murray for majority of the year, many criticized the younger players for not doing enough to challenge Federer, 37, and Nadal, 32.

With the US Open having commenced this week, the final Grand Slam of the year, the situation is still the same.

The duo is on top of the rankings while Djokovic, ranked No. 6, is having his own resurgence, as he is currently favored to win at Flushing Meadows following his wins at Wimbledon and the Cincinnati Masters. The 31-year-old Serbian would jump to No. 3 in the rankings if that were the case.

Even if Djokovic does not emerge victorious, most have Nadal or Federer winning the Grand Slam, and for Safin, it's not good to have the same players expected to win the big tournaments.

"It's quite bad for tennis," Safin recently told Spanish publication Marca. "In my time, if at 17 you did not win an ATP tournament, you were killed and now if you win a tournament when you're 25 you are a member of the Next Gen. Nadal and Federer are still at the top because the young people are very bad."

It's not the first time Safin has criticized the younger players. Toward the end of 2017, the Russian also had harsh words for the youngsters in the sport, citing how players used to retire in their thirties, rather than dominate the rankings.

"Players used to retire by the time they got to 30. At 32 you were a dinosaur," he said. "Now you see players who are still running at the age of 38. The upcoming young guys just aren’t at a high enough level. If you can still manage to run at the age of 38 and still be No 1 in the world, it means there must be something wrong with the other players."

Nadal believes the same thing as he speculated last month as to why him, Federer and Djokovic were still dominating the sport, although he was less harsh with his assessment.

"There are two options to explain the fact that three players are dominating the [tennis] circuit for so many years, and that we are in the top positions in the ranking for so many years," Nadal explained. "Either we have been special, or the emerging players have not been special enough."

"I cannot say which is correct. A generation with special players [is coming], either because they will be better than us in a short time, or because of our age," he said.