"He has just had an ongoing issue in his hind area and we wanted to get it looked at by the experts since he was going to be in Sydney anyway after Victoria.
"But he had had three fast workouts over there and we have been happy with his work since he got back to New Zealand so he will be ready for Friday for sure."
Lazarus was taken to the Cambridge workouts on Saturday and beat Risk and more importantly his own stablemate and Derby rival Chase The Dream over 2200m, his final 400m in 27 seconds.
Lazarus should start around $1.50 on Friday in a classic that drew more entries than expected.
The 12-horse field includes huge last-start Alexandra Park winners Shandale and Buster Brady, although both have fared poorly in the draws.
Lazarus's stablemate Pacing Major will start favourite in the $100,000 Breckon Farms Young Guns Final after drawing the ace. Smolda and Sky Major return in the $50,000 City Of Auckland Free-For-All, taking on Hughie Green.
Derby night has drawn strong fields with both two-year-old races having depth and One Over Da Moon back from Australia in the main trot.
One trotter going the other way is Speeding Spur, who is now the second favourite for Saturday's Great Southern Star at Melton.
Speeding Spur was powerful overcoming a 50m handicap at Alexandra Park last Friday and has only Kiwi-owned Keystone Del ahead of him in the market for Saturday's series, which sees two heats early in the night before the A$300,000 final run two hours later.
"He has improved since he was there last month and we couldn't be happier," says co-trainer John Dickie.
Meanwhile, champion filly Dream About Me will miss her first New Zealand start of the season at Addington on Thursday. The unbeaten filly was to to have contested a Nevele R Fillies heat but has a stone bruise.
Derby, $250,000
1. Walkinshaw fr Tony Herlihy
2. Lazarus fr Mark Purdon
3. Perfect Storm fr Todd Macfarlane
4. Kimani fr Zac Butcher
5. Zadaka fr David Butcher
6. Chase The Dream fr Natalie Rasmussen
7. Shandale fr Maurice McKendry
8. Buster Brady fr Blair Orange
9. Van Mara fr Simon Lawson
10. Motown fr Joshua Dickie
11. Stroke Of Luck fr Tim Williams
12. Ideal World fr James Stormont