The scandal revolves around Park's friend Choi Soon-sil, who was allegedly involved in government matters without holding an official position.
South Korea's President Park Geun-hye named a new prime minister and finance minister on Wednesday, after her administration was shaken by a scandal involving a friend accused of meddling in state affairs.
Opposition parties denounced the reshuffle as a bid by Park to divert attention from the political crisis.
Kim Byong-joon, a senior presidential secretary during former president Roh Moo-hyun's administration, is expected to replace Hwany Kyo-ahn as prime minister. The prime minister's role in South Korea is largely administrative and requires parliamentary approval.
"This situation is moving pretty quickly and I will voice my thoughts tomorrow after having listened to those around me," Kim told reporters, declining to comment further.
Park named Financial Services Commission Chairman Yim Jong-yong as finance minister and deputy prime minister. Yim, who replaces incumbent minister Yoo Il-ho, has been well-regarded by policy-makers and market participants in his current role.
Neither incumbent has been implicated in the scandal, although Yoo has been under pressure from opposition lawmakers over his close relationship with Park.
The shake-up, which included bringing in a new minister of public safety and security, did little to please the opposition.
"This replacement of the prime minister and finance minister can't be happening without discussing it with the opposition," Park Jie-won, leader of the opposition People's Party, told a party meeting.
"We won't stand by such a move to turn around the current situation with the personnel change," he said, adding that his party would boycott nomination hearings.
The scandal revolves around Park's friend Choi Soon-sil, who was allegedly involved in government matters without holding an official position, allowing her to enrich herself.
This relationship has led a growing number of opposition politicians – as well as many members of the public – to call on Park to step down, although the opposition has not called for impeachment proceedings.
Park's apology on television for giving Choi access to draft speeches during the first months of her presidency did little to deflect demands that Park reveal the full nature of her ties with Choi and whether she enjoyed favours because of her friendship with the president.
Despite numerous scandals over the years, no South Korean president has ever resigned or been successfully impeached.
If Park, 64, were to step down before the end of her five-year term, an election would be held in 60 days, with the winner serving as president for five years.