Murtagh was bullish yesterday about the chances of the Aidan O'Brien-trained favourite, who leapt into the classic picture when winning the Gallinule Stakes at the Curragh just two weeks ago.
"He's the ideal horse as he seems to have everything," said Murtagh.
"He has speed, stamina and good balance, so I'm quietly confident he's going to run a huge race.
"He's a very straightforward horse and has a good temperament.
"He's never run over a mile and a half yet so we don't quite know (if he stays), but the way he travels and relaxes in his races will give him every chance."
Murtagh, aiming to land his fourth Epsom Derby, said Jan Vermeer had come out of his race at the Curragh really well.
"He had a lovely run there and travelled well.
"I think the ground will be fine for him as he didn't seem to mind it at the Curragh when it was genuinely good to firm. I think he'd go on most ground.
"He should stay the trip and there might even be more improvement in him.”
Meanwhile bookmakers are predicting that a Derby victory for Jan Vermeer will cost the betting industry £10 million.
The layers were smiling when winter favourite St Nicholas Abbey was pulled out of the premier Classic with a muscle problem.
But Coral's Simon Clare said: "We won about £2 million when St Nicholas Abbey was scratched, but in the run-up to his defection there was a big gamble on Jan Vermeer.
"If Johnny Murtagh's mount comes home in front then, industry-wide, we're looking at a £10 million loss."
The odds look stacked against the leading English challengers, according to Derby trends and statistics. Michael Stoute’s Workforce won his maiden as a two-year-old before going down to Cape Blanco in the Dante Stakes.
But no horse beaten in the Dante has ever gone on to win at Epsom in the 52-year history of the York race. You have to go back to 1990 and Quest For Fame to find any horse who came good at the Derby after losing out in any of the recognised trials.
Another stat not in his favour is that the last 47 Derby winners had all previously won or been placed in a Group One race and Workforce has never even run in such a contest.
Henry Cecil believes Bullet Train. will run “very well”. But 39 of the last 45 Derby winners went into the race with an official rating of 113 or higher and Bullet Train is well below that mark; the other problem is that jockey Tom Queally is having his first ride in the classic and no first-timer has won the Derby since Walter Swinburn on Shergar in 1981.
Godolphin’s Rewilding is trained not by Saeed bin Suroor but by his former deputy Mahmood Al Zarooni. Godolphin are still waiting for their first Derby success, but again the stats look bad. Rewilding won the Goodwood trial and no horse winning that race has gone on to Derby glory since Troy in 1979.