Washington (CNN) A former Trump administration official who cooperated with Robert Mueller's probe is having serious second thoughts about talking to the special counsel's office, citing concerns about being named in the Justice Department's redacted version of the report.

This aide noted the White House requested that former senior officials cooperate with the Mueller probe, going as far as to hand over email addresses for those aides to investigators. That made it next to impossible to not cooperate, the aide said.

The former official scoffed at the notion that President Donald Trump would be mad at aides who talked to investigators, because Trump and his lawyers should have known that people scheduled to sit down with Mueller's team would have to tell all they know in their sessions with the special counsel's investigators.

The Trump legal team has openly discussed how cooperative they have been, even putting out a letter documenting the extent of cooperation. It's been the strategy all along to make it harder for Mueller to insist on an interview.

Now, this former official is nervously anticipating what will be in the redacted version of the Mueller report. This aide claims to have fully cooperated with the investigators, pointing out the indictments in other cases in which Trump associates had been accused of lying to the Mueller team.

Read More