Both cleared waivers at noon ET Friday.
Gerber will be assigned to Edmonton's AHL affiliate in Oklahoma City. A team source said Souray will remain in limbo as the Oilers continue to try and trade him.
Souray, 34, requested a trade after last season and was told not to attend the team's training camp while awaiting a possible move. He had four goals, nine assists and 65 penalty minutes in 37 games with the Oilers last season.
He has two years remaining on his deal paying him a $4.5 million annual salary but with a salary cap hit of $5.4 million. The Oilers put Souray on waivers in early July but found no takers.
Gerber, 35, spent last season with Atlant Moscow of the Russian-based KHL and was unable to win a spot with Edmonton. He is 111-78-21 with a 2.65 goals-against average and a .910 save percentage in 226 career NHL games with Anaheim, Carolina, Ottawa and Toronto.
Gerber is on a one-year contract that pays him $500,000 in the NHL and $200,000 in the minors.
Pierre LeBrun covers the NHL for ESPN.com. Information from The Associated Press was used in this report.