From MMAWeekly:
Canadian fighter Jason Day has had to withdraw from his planned UFC 88 match-up on Sept. 6 with Jason Lambert. A source close to the fight informed MMAWeekly.com that Day suffered an elbow and biceps injury that will require him to have an MRI to determine the extent of the injury that will keep him out of the fight.
No replacement has been announced for the Jason Day vs Jason Lambert fight and with two weeks left it will be very short notice for somebody to step up.
UFC Results will bring you full results on September 6th.