Lamar Odom -- or his lawyer -- has to appear before a judge on Friday for his DUI arraignment, but there's a major problem lurking for the two-time NBA championship star and he's in a race against time to fix it.

Odom, 33, has not retained a lawyer, despite reports that famed lawyer Robert Shapiro is representing him.

In fact, Breaking Celebrity News has learned, the man who represented O.J. Simpson in the "trial of the century" -- the slayings of Nicole Brown Simpson and Ron Goldman -- hasn't even spoken to Odom… not even once!

"Robert (Shapiro) hasn't talked to Lamar since he got his DUI arrest, or been retained to represent him," a source close to the case told Radar.

"There has been zero communication between Robert and Lamar. Robert was hired by Lamar's mother-in-law, Kris Jenner, after his arrest. The lawyer has been in touch with Khloe, but still hasn't spoken to Lamar.

"Lamar knows Robert -- and he respects him -- but it doesn't change the fact that he hasn't been hired."