That said, she can't afford to have any more Republicans vote against her without winning more Democrats to her side.
"Ms Haspel's role in overseeing the use of torture by Americans is disturbing. She has dedicated her entire life to the service of our country and has performed extraordinarily well in a number of challenging positions - often, in some of the most unsafe places in the world", Collins says, in a statement released after Wednesday's hearing.
McCain, who was held as a prisoner of war during the Vietnam War, is now home in Arizona where he's receiving treatment for brain cancer.
McCain serves as the chairman of the Senate Armed Services Committee, but is now in Arizona, where he is being treated for brain cancer and is not expected to be present for the vote on Haspel's nomination.
Haspel, 61, was nominated by Trump in March after former CIA Director Mike Pompeo was nominated and later cleared as secretary of state.
Fox News' Neil Cavuto asked Manchin why he supported Haspel's nomination, which has met opposition due to her roles in enhanced interrogation during the Bush administration.
"Under my leadership Central Intelligence Agency will not restart such a detention and interrogation program", Haspel said in her opening statement at a Senate hearing, addressing one of the biggest skepticism against her. "Think of that, in these very risky times, we have the most qualified person, a woman, who Democrats want OUT because she is too tough on terror. But as I have argued many times, the methods we employ to keep our nation safe must be as right and just as the values we aspire to live up to and promote in the world".
She was summoned to the White House on Friday for a meeting over her history with the CIA's controversial interrogation program - which employed techniques such as waterboarding that are widely seen as torture - and signaled that she was going to withdraw her nomination.