Lawyer Alan Dershowitz suspects special counsel Robert Mueller's team of federal prosecutors is preparing to subpoena President Trump.

"I do. I think they’re gearing up for what will be a difficult legal battle," Dershowitz, a fierce critic of Mueller's federal Russia investigation, said during an interview Tuesday with CNN.

Dershowitz's comments follow a CNN report Monday in which Rudy Giuliani, Trump's lead personal attorney, said he hasn't heard from Mueller's office in nearly three weeks as the two sides negotiate terms for a possible presidential voluntary interview as part of the ongoing Russia probe.

[Rudy Giuliani: We'll fight a Mueller subpoena all the way to the Supreme Court]

Dershowitz was asked Tuesday whether the radio silence could indicate Mueller's team may be considering another means of obtaining Trump's testimony.

"I suspect they have come to the same conclusion I came to several weeks ago that the tactic of the Trump team — I have no inside information on this — but the tactic of the Trump team is to make the Mueller team an offer they can’t accept so that in the end there will be no sit-down and the Trump team can say, 'Look, we made them an offer. It’s their fault. They didn’t accept it,'" Dershowitz said.

"I suspect that Mueller is onto this tactic and is now looking forward to filing some kind of a legal action, compelling the president to appear in front of a grand jury," he continued. "You can’t compel the president to sit down with the special counsel, but you can compel him to come in front of a grand jury."

Dershowitz added Trump's outside legal counsel would contest any such move and that "ultimately" the courts would decide whether the president will have to testify.

Giuliani told CNN on Monday he figured Mueller's prosecutors were "planning something," but said that could include them issuing a report without a Trump interview, subpoenaing the president to talk to them, or staying the course by negotiating the conditions for a potential sit-down.