Set for October 4 from Stockholm, Sweden and the Ericsson Globe, the event does not have a main event yet.
Siver (21-9) has been serving a suspension for a failed drug test last December after a win over Manny Gamburyan. The German had the result changed to a no-contest and was suspended nine months after human chorionic gonadotropin was found in his system.
The veteran Siver is 10-6 in his UFC career and 2-1 with the one no-contest in his last four fights.
Whiteford (11-2) had his 10-fight win streak snapped in 2013 when he debuted with the UFC against Jimy Hettes. He rebounded earlier this year, scoring a decision victory over Daniel Pineda.
Below is the list of fights announced for the card:
Welterweight: Amir Sadollah vs. Nico Musoke
Featherweight: Niklas Backstrom vs. Mike Wilkinson
Featherweight: Ernest Chavez vs. Zubaira Tukhugov
Featherweight: Dennis Siver vs. Robert Whiteford