Gagner was called up from AHL Bakersfield on Wednesday, Jason Gregor of Sports 1440 Edmonton reports.
The Oilers are bolstering their forward depth ahead of their last two games of the regular season. The 34-year-old had 10 points across 27 top-level games earlier in the campaign. He'll likely fill a bottom-six role at some point during the team's last back-to-back of the regular season.