Sitak and his Dutch partner Wesley Koolhof have another day off before they face the 5th seeds Colombians Juan Sebastian Cabal and Robert Farah. It's the team who Venus and then partner Ryan Harrison beat in the semi-finals at Roland Garros last year.
The Colombians are in fine form having won the Italian Masters 1000 title late last month and losing in the semi-finals a week earlier in Madrid. They finished runner up at the Australian Open for their best Grand Slam result in January.
Meanwhile New Zealand's Erin Routliffe is set for another jump in the WTA doubles rankings after capturing the title with Mexican Victoria Rodriguez in the ITF Futures tournament in Hua Hin Thailand.
The 23 year old Kiwi and Rodriguez have beaten Thai third seeds Peangtarn Plipuech and Nicha Lertpitaksinchai 7-5 306 10-5 in the final.
The result is expected to see Routliffe climb from her current position of 136 to 122 in the rankings. She has won seven doubles titles so far in 2018.
Meanwhile Kiwi Rhett Purcell has captured his maiden ITF doubles title in China. Playing at the US 25,000 Futures tournament in Luzhou Purcell and Germany's Sami Reinwein have beaten the Philippine Chinese pair of Francis Alcantara and Sun Fajing 7-5, 6-3 in the final. Purcell now heads to Japan for another ITF 25,000 tournament next week.