Siver (21-9, 1 NC) is coming off a suspension after testing positive to human chorionic gonadotropin (hCG) following his UFC 168 bout against Manny Gamburyan on Dec. 28. He originally won the fight by unanimous decision, but the result was later ruled a No Contest after Siver’s failed drug test.
Whiteford (11-2) made his UFC debut in October 2013, losing by submission to Jim Hettes in the second round. He rebounded from his debut loss with a unanimous decision win over Daniel Pineda at UFC 171 on March 15.
UFC Fight Night 53 takes place at Ericsson Globe Arena in Stockholm on Oct. 4. It will be the third event the UFC has hosted in Sweden. Stockholm has become an annual stop for the fight promotion since their first event there in April 2012.