According to famous reporter Marc Stein, the Nuggets are optimistic that they can retain center Valanciunas.
"The Nuggets are optimistic that Valan will stay in Denver this season, and the Nuggets signal Varan behind the scenes that they do not intend to let him terminate his NBA contract," Stein wrote.
According to regulations, if Valan wants to play in Europe, he needs the Nuggets to agree to terminate the contract + FIBA will open a clarification letter.