Hunter went on the DL retroactive to May 21 with a left groin strain. He's 1-1 with a 6.06 ERA in 19 appearances, with 11 runs, 25 hits allowed, five walks and 15 strikeouts in 16 1/3 innings.
Zach Britton has taken over as closer, and Hunter figures to work more in a set-up role.
Hunter pitched in one rehab game at Single-A Delmarva, striking out two and hitting a batter last night.
Meek is 0-2 with a 6.39 ERA in 13 relief appearances, with nine earned runs (10 total) and 15 hits in 12 2/3 innings. He posted eight consecutive scoreless appearances to start the season.
The Orioles designated Meek off the 25-man roster May 16 and outrighted him to Triple-A Norfolk on May 28, removing him from the 40-man. They purchased his contract on Friday and transferred Rule 5 pick Michael Almanzar to the 60-day disabled list.
Since Meek has an option remaining, the Orioles are able to send him down today without placing him on waivers.
The Orioles signed Meek to a minor league deal on Feb. 6. He was an All-Star with the Pirates in 2010.