Jones left the field during Baltimore's 8-1 win over the Twins Tuesday and the Twins' team doctor was summoned to examine him, The Baltimore Sun reported.
He was transported to Hennepin County Medical Center for tests.
Early Wednesday, Jones tweeted: "Back from hospital. Wasn't as serious as it sounded. Glad everything is in order. Appreciate the support and well wishes. Back at it manana."
The Orioles said it was believed Jones' pains were muscle-related and not a cardiopulmonary condition.
"After talking to a few people, he was feeling a little down, just weak," Orioles manager Buck Showalter said. "After his first at-bat and everything, it didn't get any better. [We] didn't like what he was describing, and so we decided to get him out of there and let the doctors get a look at him."
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