Actually Trump’s own words from his interview when Rosenstein first appointed Mueller speak volumes about how he feels about them both:
https://www.nytimes.com/2017/07/19/us/politics/trump-interview-sessions-russia.html
Mr. Trump was also critical of Mr. Mueller, a former F.B.I. director, reprising some of his past complaints that lawyers in his office contributed money to Mrs. Clintons campaign. He noted that he actually interviewed Mr. Mueller to replace Mr. Comey just before his appointment as special counsel.
He was up here and he wanted the job, Mr. Trump said. After he was named special counsel, I said, What the hell is this all about? Talk about conflicts. But he was interviewing for the job. There were many other conflicts that I havent said, but I will at some point.
The president also expressed discontent with Deputy Attorney General Rod J. Rosenstein, a former federal prosecutor from Baltimore. When Mr. Sessions recused himself, the president said he was irritated to learn where his deputy was from. There are very few Republicans in Baltimore, if any, he said of the predominantly Democratic city.
He complained that Mr. Rosenstein had in effect been on both sides when it came to Mr. Comey. The deputy attorney general recommended Mr. Comey be fired but then appointed Mr. Mueller, who may be investigating whether the dismissal was an obstruction of justice. Well, thats a conflict of interest, Mr. Trump said. Do you know how many conflicts of interests there are?
Rod Rosenstein was appointed by President Trump. In fact, Trump thought highly enough of him that he refused to accept his resignation from his prior position as the U.S. Attorney for the Maryland District when Jeff Sessions asked for the resignations of all these U.S. Attorneys back in February.
That NYT interview from July 2017 was one of the wackiest media reports of the year. After reading some of those quotes and comparing them to the facts as they actually happened earlier in the year, I concluded that Trump agreed to the NYT interview for the sole purpose of blowing smoke up everyone's @ss. LOL.