Wojnarowski reported Leonard and Danny Green will head to Toronto in exchange for DeRozan, Jakob Poeltl and a protected 2019 first-round draft pick.
Per Wojnarowski, the first-round pick is protected for the 20th overall selection and above, and after a year, it will turn into two second-round draft choices. Zach Lowe of ESPN also pointed out Toronto would receive $5 million cash from San Antonio in the deal, to cover the tax hit related to Leonard's trade kicker.
Talks between the teams have "been close for days and nearly fallen apart several times," per Wojnarowski.
Haynes noted the Raptors reportedly told DeRozan during a meeting at the Las Vegas Summer League that he wouldn't be traded.
Seemingly in response to the rumor of getting dealt to San Antonio for Leonard, DeRozan wrote the following Wednesday morning on his Instagram story: "Be told one thing & outcome another. Can't trust em. Ain't no loyalty in this game. Sell you out quit for a little bit of nothing...soon you'll understand... Don't disturb..."
It was first reported by Jabari Young of the San Antonio Express-News in June that Leonard had requested a trade from San Antonio.
Leonard appeared in just nine games last season due to a quad injury, and Shams Charania of Yahoo Sports reported his discomfort with the Spurs' handling of his injury was the reason for his desire to leave.
Since Leonard can become a free agent next offseason, the Raptors would be taking a significant risk in acquiring him.
Wojnarowski noted Raptors president of basketball operations Masai Ujiri is making the deal "with a determination that he can sell Leonard on re-signing with the Raptors next summer in free agency."
Toronto can offer Leonard a five-year, $190 million contract next offseason, while being able to sign a four-year, $141 million deal with any other team.
Aldridge reported that a source said a "long-term stay in Toronto past this year is going to be 'a very tough sell.'"
Per Wojnarowski and Haynes, Leonard has "been clear" about his intentions to sign with his hometown Los Angeles Lakers next offseason.
Although the Raptors finished with a franchise-record 59 wins last season and earned the No. 1 seed in the Eastern Conference, they were bounced in the second round of the playoffs by the Cleveland Cavaliers.
The Raptors are in the midst of the best run in franchise history, with five consecutive playoff appearances, but they have just one Eastern Conference Finals appearance to show for it.
DeRozan, 28, has been named an All-Star in four of the past five seasons, and he is coming off another strong campaign.
Last season, he averaged 23.0 points, 5.2 assists and 3.9 rebounds per game as part of a dynamic backcourt alongside Kyle Lowry.
Since that combination has not produced results in the playoffs, however, the Raptors entered the offseason willing to "explore all options" in terms of potential trades, per the Toronto Sun's Ryan Wolstat.
If the 27-year-old Leonard is healthy, he may represent an upgrade for the Raptors in 2018-19, who have seen their odds to win a championship increase since word of the deal, via Oddsshark:
He is a two-time Defensive Player of the Year and a one-time NBA Finals MVP who finished third in the NBA MVP voting in 2016-17 after averaging 25.5 points, 5.8 rebounds, 3.5 assists and 1.8 steals per game.
While Leonard can become a free agent next offseason, DeRozan has two years remaining on his deal and a player option for 2020-21.
DeRozan would join forces with All-Star big man LaMarcus Aldridge in hopes of leading the Spurs to their 22nd straight playoff appearance.