Hu was optioned back to Triple-A Durham on Tuesday, Marc Topkin of the Tampa Bay Times reports.
Hu was sent back to Durham after just one day with the big club, with the Rays calling up southpaw Justin Marks to take his roster spot. The 23-year-old made one appearance during his brief stint, allowing one (unearned) run while striking out one and walking one in two-thirds of an inning. He'll remain a top option to return to the Rays should they need an extra bullpen arm in the future.