Both players are the subject of interest from Bramall Lane after Wilder, who has already signed Ched Evans, Nathan Thomas and Enda Stevens, overhauls the League One champions’ squad ahead.
Although their parent clubs have so far refused to relent, Wilder last night suggested United are planning to continue pursuing the duo following a meeting of their transfer negotiation committee.
“We’ve put a couple of bids in and so hopefully that will develop,” he said. “If not, we’ll move on to other targets. “We’ve got a recruitment meeting and myself, the staff, (head of football administration) Carl Shieber and (chief executive) Steve Bettis speak every other day.”
Although United have publicly been warned-off Holmes - Charlton’s reigning player of the year - and Leonard, who holds the same title at Roots Hall, their decision not to abort the chase indicates they are convinced the duo are privately interested in moving north.
“We want to get 75 per cent done early and then leave a couple until the end of the window,” Wilder said.