The 7-foot Valanciunas is averaging 12.8 points and 7.2 rebounds this season.
According to Adrian Wojnarowski of ESPN, the Raptors are in the final stages of a blockbuster deal to obtain centre Marc Gasol from the Memphis Grizzlies for Jonas Valanciunas, C.J. Miles, Delon Wright and a future second round draft pick.
Gasol isn't the player he once was - a three-time All-Star and a perennial All-NBA candidate - but the Spaniard has the potential to be what Valanciunas was and more.
The Grizzlies have been open to trading Gasol and star guard Mike Conley for a few weeks now.
Gasol heads north of the border averaging 15.7 points with 8.6 rebounds per game.
Leonard also has a player option for 2019-20, worth $21 million.
Memphis sent Gasol to the Raptors in exchange for Jonas Valanciunas, a person told The Associated Press on condition of anonymity because the details couldn't be announced until approved by the National Basketball Association.
Valanciunas, who was set to make his return from a broken hand on Thursday night, said he was aware of the trade rumours but wasn't anxious.
Instead, they just matched the 22 wins from last season on Tuesday in a game Gasol left the arena early after being benched without explanation. "I love Toronto and I want to stay here". Toronto (39-16) is two games back of the Milwaukee Bucks (40-13) atop the Eastern Conference. He's now averaging 4.7 assists per game, the highest mark of his career and the second-most among centres this season behind only Nikola Jokic.
Wright, a 6-foot-5 point guard, is averaging 6.9 points, 2.6 rebounds, and 2.2 assists per game in his fourth National Basketball Association season.