"It's good that Marcus [is playing well] but it will be like playing anyone else and they just have to focus what they are doing and try to execute as well as they can," said Venus.
Venus and Raven Klaasen (South Africa) play Daniell and Dutchman Wesley Koolhof in the first match on court 8 from 1pm.
Meanwhile Sitak and his American partner Austin Krajicek were knocked out on Friday night in the second round.
They went down 6-4, 7-6 (5) in 96 minutes against big serving American pair Sam Querrey and Ryan Harrison.
It was tight throughout but Sitak and Krajicek were unable to force any break point opportunities against their opponents' serves, while being under considerable pressure on their own serve.
Games went with serve until the 10th game of the opening set when Sitak, after saving one break point, was broken at the second attempt to lose the set in 33 minutes.
Sitak was 0-40 down in his opening service game at 1-2 in the second set. He fought his way back to deuce and saved another break point before some big serving helped him out of trouble to hold serve.
Krajicek then saved three break points in his next service game and Sitak saved a match point at 5-6, 30-40, eventually holding to take the second set into a tie break.
But Querrey and Harrison were always favoured in the breaker, with their powerful serves.
The American duo jumped out to an early lead, which they never relinquished, to seal their passage to the second round.
After strong 2018 campaigns, all three New Zealanders all well positioned to make inroads again this year, with Venus at No 15, Sitak (No 35) and Daniell (No 44).
Young Kiwi Valentina Ivanov has drawn a tough opponent in the opening round of the Junior Girls singles.
The 17 year old winner of the New Zealand Championships will face Thai 5th seed Mananchaya Sawangkaew who is ranked 18.
