David Nalbandian stood by his criticism of the sport's governing body after being at Queen's Club.
The Argentine apologised for kicking an advertising board that injured a line judge but also criticised the ATP.
"When somebody else makes a mistake nobody does anything," he said later. "That's why sometimes a player doesn't feel that the ATP defends the players.
"Sometimes you get angry, sometimes you cannot control when that happens."
The 30-year-old was leading 7-6 (7-3) 3-4 when he smashed a panel in front of Andrew McDougall's seat after losing his serve, causing the line judge's leg to bleed heavily.
He was immediately disqualified, although sections of the 6,000-capacity crowd booed and chanted "play on", and was left to explain his actions to Sue Barker live on BBC One.
"I am very sorry, sometimes you get frustrated on court," he said. "There are a lot of rules and sometimes they don't do anything. The rule book is very big and I can tell you the ATP do a lot to the players and nothing happens."
Afterwards, the former Wimbledon finalist was asked to explain why he had criticised the ATP and responded by saying it was difficult for the players to have any influence.
"At the beginning of the year you have to sign that you agree with everything the ATP says," he said. "And sometimes you don't. If you don't want to sign, you cannot play ATP tournaments so you don't have a chance to ask [about something] or to change something.
"So if you don't sign, you don't play and you have to agree 100% with what the ATP says."
ATP supervisor Tom Barnes said he had no other option but to disqualify Nalbandian once he saw the injury and revealed the Argentine would lose ranking points, prize money and be fined for the incident.
"It is unsportsmanlike conduct, and the supervisor has the authority to declare an immediate default," said Barnes.
"Once I saw that the line judge was injured, I didn't have any other option."
Tournament director Chris Kermode described Nalbandian's disqualification as a "clear-cut case" but said the player was afterwards "very apologetic".
"It's not the way we wanted to finish the final, by any means," said Kermode. "I think some sections of the crowd didn't see how bad it was. Anyone who saw it on the television... it was sort of a red card in football.
"I can understand the crowd's frustration. They paid money to see it. It was the best weather day we've had and great tennis so I can understand their frustration but from a rules perspective, there was absolutely no other choice."