McClay was not prepared to say who he was backing for the top job.
As of this morning , Simon Bridges, Judith Collins, and Amy Adams had all announce their candidacies.
McClay wanted to take time to consider the different candidates, and would be seeking feedback from party members in the Rotorua electorate.
He also believed more of his colleagues may announce leadership bids.
Those believed to be weighing up a bid are Mark Mitchell and Steven Joyce.
Dr Jonathan Coleman ruled himself out on Thursday.
McClay previously backed English's bid for the leadership following Sir John Key's resignation in December 2016.
The National Party caucus has two weeks to pick a new leader, with English set to leave Parliament on February 27.
McClay said there was a "huge amount of discipline" in the caucus, and he believed the selection process would not lead to any divisions in the party.