  I study the behavior of the gauge-invariant gluon bi-local operator with
space-like separation at large longitudinal distances. Performing the Fourier
transform, I also calculate the behavior of the pseudo and quasi gluon PDF at
low Bjorken $x$ and compare it with the leading and next-to-leading twist
approximation. I show that the pseudo-PDF and quasi-PDF are very different in
this regime and that the higher twist corrections of the quasi-PDF come in not
as inverse powers of $P$ but as inverse powers of $x_B P$.
