Valanciunas reportedly declined to exercise a player option worth $17.6 million for next season in order to negotiate a longer-term deal with Memphis.
The Grizzlies acquired the 27-year-old Lithuanian in the midseason trade that sent veteran big man Marc Gasol to the Toronto Raptors. Valanciunas had one of the best stretches of his career in 19 games with Memphis, averaging 19.9 points and 10.7 rebounds before he was shut down for the final five contests of the season with an ankle sprain.
Selected fifth overall by the Raptors in 2011, Valanciunas has averaged 12.1 points and 8.5 rebounds in seven NBA seasons.
Though Valanciunas and the Grizzlies can verbally agree on a new deal as soon as Sunday night, they can't officially sign a new contract until July 6, when the league's moratorium period ends.