The Rangers midfielder was on a month's loan deal with The Chairboys but he sustained a torn calf muscle in training which is expected to keep him sidelined for about six weeks.
Wycombe boss Gary Waddock has, however, not ruled out Ainsworth returning to Adams Park once he is fit again.
"I would love to keep him longer term and we'll see what develops when he recovers," he told his club's official website.
"I would like to thank him for all his efforts during his stay with the club.
"The impact he had in only a short spell was fantastic and he gave everyone a lift.
"He played his part and we wish him a speedy recovery."