Hendriks, who was scheduled to start Sunday's game against the Orioles, was admitted to the hospital on Saturday. Right-hander Anthony Swarzak made the start in his place.
"They are talking about keeping him another night," Twins manager Ron Gardenhire said. "Terry [Ryan] talked to him and told him, 'If you're feeling fine and you want to try to make our flight back, you're the only person that can get [you] out of the hospital.' Our doctors are talking to their doctors, but they're talking about keeping him an extra night. They don't think it would be a good idea to get on an airplane."
Gardenhire said the other problem will be figuring out when to slot Hendriks back into the rotation, as he's lost weight and hasn't thrown a baseball since Friday.
"We have to make sure he's going to be OK strength-wise before we get him back out there," Gardenhire said. "He hasn't touched a baseball in a few days. ... plus, he's been pretty sick. He's going to have weight loss, the whole package. So we're just going to have to figure that out as we go."
Gardenhire said that if Hendriks isn't ready to rejoin the rotation in five days, Swarzak would stay in the rotation in his place.