It's not that the Bulls have made it clear that they're looking to make a move, it's just that the deadline to release Robinson and not take a cap hit is fast approaching.
As noted by Johnson, there's also the small matter of rookie Marquis Teague. When given extended minutes, Teague has played well, and coach Tom Thibodeau elected to start him in the second quarter at point guard against the Celtics last time out.
Robinson has a non-guaranteed contract, and if the Bulls were to waive him prior to Jan. 10, they would not receive any kind of penalty. According to Johnson, that has been an option from the time they actually signed Robinson. On Jan. 10, Robinson's contract becomes fully guaranteed. Teague might earn himself a bigger role if he can keep up his strong play in the meantime.