Boyd, who has hit 17 goals this season for Killie, is the SPL's leading marksman and the Rugby Park club have admitted a 'substantial bid' has been made by a championship club.
It is believed that Wednesday have bid around £750,000 for the player, a bid far higher than what Cardiff tabled in the summer although his boyhood club Rangers are also in the frame.
And with the striker out of contract at the end of the season, Kilmarnock's boss Jim Jefferies could cash in on his prized asset.
He said: "We've had a very good offer from a Championship side, a big offer and the offer was accepted. It will be a great offer for the club but it has to suit Kris Boyd. You can't force people to go
"I've never had an offer from Rangers. Maybe the chairman knows something I don't know but he keeps me up-to-date."
Wednesday are also giving trialists a go in a few friendlies to be played behind closed doors - and after watching yet another late capitulation against Ipswich at the weekend, new faces would be a very welcome addition.