Melvin announced after the A's 3-1 win over Texas that Phegley is going on the disabled list while Hahn will be called up from Triple-A Nashville to start Tuesday in the second game of this three-game series with the Rangers.
Oakland had to make the move with Phegley in order to make room for Hahn, who was optioned to the Minors on May 8. According to Major League rules, players sent down must stay in the Minors at least 10 days before getting called back up unless they are replacing someone going on the disabled list.
Phegley, who has not played since May 9, was the logical choice. He underwent an MRI test last week after complaining of pain behind his knee and received a cortisone shot Friday. Melvin noted before Monday's game that Phegley had been making progress .
"He is getting better, feels better," Melvin said. "Just not in a position where he's playing yet."
Phegley, who originally hurt his knee last month in Toronto, is batting .270 in 13 games as the primary backup catcher behind Stephen Vogt. He also made a rare appearance as a relief pitcher when he retired two batters -- one via strikeout -- against Boston on May 8.
• Infielder Jed Lowrie (right shin bruise) did some on-field activities, one day after hitting off a tee. Lowrie isn't eligible to come off the disabled list until May 25. "We still have a while to go … but the fact that he's doing some baseball activity today is encouraging," Melvin said.
• Mark Canha has received a second opinion on his sore left hip but Melvin is uncertain what the next step will be for the Oakland infielder. Canha is scheduled to meet with team doctors before deciding whether or not to have surgery.
Michael Wagaman is a contributor for MLB.com based in Oakland. This story was not subject to the approval of Major League Baseball or its clubs.