Khan had been expected to fight European champion Paul McCloskey, but the Irishman stepped out of the running after receiving what his promoters called "a derisory" offer.
Now Bradford man Witter, a former WBC world light-welterweight champion, has said his camp has been approached about making a fight and that he would be willing to drop to Khan's super-lightweight.
"My manager John Ingle spoke to me about the Khan offer, I'm up for this 100 per cent. It would be an opportunity too good to turn down fighting for a world title again," he told Sky Sports.
"I'm fighting on the 19th February in Canada at welterweight for the first time and I'm on the weight now at 10st 7lbs which is usually what I weigh three weeks before making the 10st limit, so I don't see any problems doing it again," he said.
"Training has been perfect and sparring the likes of Kell Brook has sharpened my skills.
"Khan, you have never boxed anyone with my experience, calibre and credentials so if you want to start playing with fire be careful you might get burnt."