The 33-year-old, who moved to within two of Roger Federer's record 20 Grand Slam triumphs with his 12th French Open earlier this month, said his qualms over Wimbledon organizers modifying the seedings according to grass court form rather than adhering to the world rankings, were valid as it is the only Grand Slam event to do so, AFP wrote.
Nadal has been leap-frogged by eight-time champion Roger Federer in the seedings with the Spaniard seeded three, one below his ranking of second in the world.
He believes men's tour ruling body the ATP should use their influence that comes with giving Wimbledon 2000 ranking points to affect how they seed the players.
"I respect all the situations," said Nadal at his pre-Wimbledon press conference on Saturday.
"The stuff is about the ATP. We give two thousand points to this event.
"We let them to do whatever they want. That's something that I don't understand, because I can't create an impact, not by myself."
Nadal, the 2008 and 2010 Wimbledon champion, said he was also worried the impact that altered seedings could have on the end of season rankings on players such as Alexander Zverev or Dominic Thiem.
Last year's beaten finalist Kevin Anderson has been seeded fourth even though he has had an injury-affected season and is ranked at eight in the world, below Zverev and French Open finalist Thiem.
"Of course, it can create an impact in the rankings at the end of the year," said Nadal,
"For example for Sascha (Zverev), for Dominic.
"It is not only about grass. The season is not only on grass.
"All the players work so hard to be where they are, then arrive here, they see a possibility to be in a tougher draw because of that."