The frontman worked with the Bees head coach at former club Excelsior and scored 17 goals in 16 games, while the Bees need a striker to provide competition for Andre Gray.
Since his move to Forest, Veldwijk is yet to score and it had been suggested that Dijkhuizen may offer him a way out.
However, he said: “We haven't spoken about him. He scored a lot of goals and came to England. I don't know what's gone wrong for him over here. He's only played a few times.”
Gray's proportion of Brentford goals
The Bees boss has made it clear that he wants to see a bigger squad at Griffin Park next season after Brentford only used 24 players in their entire Championship campaign last season.
He added: “I think we need to have a bigger squad because there's a lot of games. We need a good quality of player.
“You might need to make a change when you play Saturday-Tuesday-Saturday. Sometimes, you have to rotate it. Not six or seven changes but two or three is good I think.”