Eflin (knee) was activated from the disabled list and optioned to Triple-A Lehigh Valley on Tuesday.
He allowed just one hit over five shutout innings while striking out six and walking none in a rehab outing for High-A Clearwater last week, but as a 23-year-old who has not pitched at that level since 2014, that is less impressive than it looks on paper. Eflin should slot into the Triple-A rotation and await an opening at the big-league level.