The NHL announced on Wednesday that it was cancelling the trade that sent forward Evgenii Dadonov from the Vegas Golden Knights to the Anaheim Ducks because it violated his limited no-trade clause.

Before Monday's NHL trade deadline, Vegas moved Dadonov, a 33-year-old right winger, to the Ducks along with a conditional second-round pick for defenseman John Moore and the contract of forward Ryan Kesler, who played his last NHL game in 2019. The Ducks would select whether to receive Vegas' second-round pick in either 2023 or 2024.

After burying Moore's salary in the AHL, Vegas stood to clear $3.375 million in salary-cap space.

But hours after the trade was announced, the Golden Knights said they had "become aware of an issue with respect to the trade. We have been consulting with the league office."

The issue involved Dadonov's limited no-trade clause, which was included in a contract he signed in October 2020 with the Ottawa Senators. According to a source, the Senators failed to disclose that clause when Dadonov was traded to the Golden Knights in July 2021. Hence, both Vegas and the NHL believed he could be legally traded to the Ducks.

But Dadonov and his agent claimed that Anaheim was on his 10-team no-trade list and that the list had been submitted to Ottawa for this season by the stated deadline in the contract. They went to the NHL Players' Association, and the NHLPA disputed the validity of the trade with the NHL on Monday.

The NHL announced on Wednesday that "the trade could not be concluded because Dadonov's contract includes a limited no-trade clause, which has not been complied with."

Not long after the announcement was made, Anaheim general manager Pat Verbeek issued a statement through the team.

"We respect and accept the decision made today by the NHL with regard to our trade with Vegas on Monday. Evgenii Dadonov is a player we thought could help our team this year and beyond," he said. "We will move forward and welcome John Moore to our organization once he's healthy and ready to return."

The rejected trade is a blow to the Golden Knights, who were trying to remove Dadonov's $5 million contract from their salary cap in order to bring back players such as forward Mark Stone and defenseman Alec Martinez from long-term injured reserve. The Knights have lost seven of their past 10 games and are currently out of a playoff seed in the Western Conference.

Vegas would need $9.1 million in cap space to activate Stone and $4.8 million for Martinez. The Knights do have other injured players whose contracts could be moved to long-term injured reserve in their place to open up cap room, such as winger Max Pacioretty and forward Reilly Smith.

It's expected they'll try another trade with a team that isn't on Dadonov's list and would be willing to take on his salary-cap hit for this season and in 2022-23, the last year of his contract. Teams can make trades after the NHL trade deadline, but Dadonov would be ineligible to play for the rest of this season or postseason in 2021-22. He would still collect his salary.

Dadonov has 27 points in 62 games this season for the Knights, who acquired him in July 2021 for a 2022 third-round pick and defenseman Nick Holden.