Myers, who was placed on the 10-day DL on April 3, still is dealing with nerve irritation in his right arm and had not resumed swinging a bat as of Monday.
"I don't expect him to come off right at 10 days," Padres manager Andy Green told reporters Monday, according to the San Diego Union-Tribune. "He's going to have to swing a bat for a few days. The longer it gets, the more likely a rehab assignment becomes as well. ... We're hoping. It's not coming as quickly as we'd like it to."
Myers also has not started throwing yet, and the Padres want him to be able to throw from the outfield without discomfort before activating him from the DL.
Myers, 27, had three hits, including a home run, in 12 at-bats this season before heading to the DL.