The long-time lawyer, Jay Goldberg, according to the article, "cautioned the President not to trust Cohen. On a scale of 100 to 1, where 100 is fully protecting the president, Cohen 'isn’t even a 1,' he said he told Trump." Goldberg spoke directly to The Wall Street Journal on the record to confirm the call.
The piece goes on to note that Goldberg "said the volume of correspondence taken and the potential pressure the government can bring to bear on Mr. Cohen to testify put the president in more potential peril from the Cohen matter than from special counsel Robert Mueller’s investigation."
While Cohen has made public statements that he would never betray Trump, Goldberg isn't buying things would stay that way, given federal prosecutors in Manhattan have a long history of flipping reluctant mob witnesses.
If Cohen does eventually flip, this could be as significant as when Richard Nixon's lawyer John Dean flipped on him and sang like a birdie to prosecutors -- or possibly even bigger. Dean arguably did the most damage to the President of the many witnesses who testified against him.
Of course, all this discussion compels us to ask "If Trump didn't break any laws nor commit any crimes, why is he so worried that the Cohen investigation will be his undoing?"