Now as his fellow draftees-to-be - including fellow international rising stars Enes Kanter of Turkey and Congolese Bismack Biyombo - travel across North America to try out for various teams, Valanciunas is getting some much needed rest after what has been a long and gruesome season.
However, the 2.11m forward/centre will be back out on the court very soon as he readies himself for his fifth consecutive summer of national team duties at the junior leve, taking part in the FIBA U19 World Championship in Latvia.
From 2007 to 2010, Valanciunas experienced a great deal of success in the junior European Championships.
He led Lithuania to a gold medal at last summer's U18 event - in front of his home crowd of Vilnius - and at the 2008 U16 tournament in Chiety, Italy.
This is the kind of winning record that bodes well for Lithuania's U19 head coach Kazys Maksvytis, who hopes he can call on the tried and tested Valanciunas.
He has shown the same winning mentality and resolve for Lietuvos Rytas ever since he joined them from Perla Vilnius in January 2010, helping them to a league title and being selected to the All Star Game twice.
What Valanciunas - who boasts an impressive 2.25m wingspan - does after the FIBA U19 Championship remains to be seen.
He is expected to be a lottery pick in the NBA Draft on 22 June, with some experts ranking him as high as the third overall pick.
However, it remains to be seen whether he will make the jump to the NBA right away or play out the remainder of his contract at Lietuvos Rytas.
He has said that he would only leave Vilnius for the NBA.
Whatever Valanciunas decides to do, one thing is sure: those in attendance at the FIBA U19 Wirkd Championship in Latvia will be in for a real treat.
Check out Valanciunas' highlights from the LKL Finals
And here he is showing why he was the MVP at the 2010 U18 European Championship
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