Armstrong (neck) was activated off the 60-day injured list Saturday.
A neck injury has kept Armstrong out all season, but he could be a key piece of the Rays' bullpen the rest of the way. After being released by the Marlins last May and returning to Tampa Bay, he recorded a 3.60 ERA backed by a 26.0 percent strikeout rate and 6.0 percent walk rate the rest of the way, earning a pair of saves. Jose La Sorsa was designated for assignment to create space on the 40-man roster.