No play has been possible since the evening session on day two and organizers abandoned any hope of play on Tuesday well before the scheduled end.
Brathwaite had impressed before James Pattinson (2-67) cleaned up his off stump, West Indies reaching 248-7 at stumps with only 11.2 overs bowled on Monday.
O’Keefe will partner front-line spinner Nathan Lyon and the left-arm finger spinner said he was confident the pair could succeed bowling in tandem against the Caribbean tourists.
The West Indies, who will be playing in their first Test at the Sydney Cricket Ground in 15 years, will be trying to prevent the Australians from sweeping the series and possibly returning to the top of the Test rankings.
It was his second consecutive half-century after scoring 59 in his debut test at Melbourne last week – and became the first West Indian since Darren Bravo in 2010 to score 50s in each of his first two tests.
That brought Samuels to the crease in a failed attempt to breaking a run of eight Test innings without getting over the 20-run mark.
Kraigg Brathwaite added 27 for the fifth wicket with Ramdin before he too perished at the hands of Lyon, gloving a cut to captain Steve Smith at first slip off one that bounced.
The ongoing showers at the SCG Test between Australia and the West Indies will not leave Cricket Australia out of pocket despite the organisation shelling out two days of full refunds.
The senior batsman continued his wretched run of low scores in the series when he was needlessly run out for four.
Samuels has made only 35 runs, at an average of seven, in his five innings this tour.
To compound Samuels’ and his team’s woes, rain immediately forced the players from the field and kept them off until tea was taken.
The dismissal fo Brathwaite by Lyon was also the offspinner’s 100th Test scalp on Australian soil, a feat only matched by 4 other men.
Shai Hope (9), a late selection for the injured Rajendra Chandrika who injured a groin in the warm-up, was the only wicket to fall in the opening session, caught behind off Josh Hazelwood (1 for 35). “He’s a great team man and felt he would be letting the team down (if he played)”.
It was a just reward for O’Keefe who has been on the fringe of Australia selection for several years but has previously played just the single Test against Pakistan in Dubai in 2014.