Opposing teams looking for our team's weaknesses. And they often see the weakest link in Valanciunas. Then they set play against Valanciunas in hope he will make mistakes or foul.
That example when Kaman dropped 9 in first and 6 in rest, just shows that they changed tactics, when Valanciunas was out. He needs more support, help from other players, not to be bench after first mistake.
And to have true picture should be counted not just points, but points and attempts.
Lots of people agree that Valanciunas play strongest in P&R, not in defence or distance jump shots. But he has't got chance to play P&R yet.