Jonathon Niese left tonight's game with an elevated heart rate. #NYMvsHOU— New York Mets (@Mets) September 27, 2014
It's not the first time Niese has experienced something of this nature. In 2012, he had to leave a game against the Cardinals early, also in the sixth inning, for the same reason. Initial tests in 2011 did come back negative. A year prior to that against the Rangers, he was pulled, initially saying that he was simply "overheated". Fortunately, initial tests in 2011 did come back negative.
There's obviously no word yet of a timetable as far as further tests are concerned, and we'll certainly keep you posted on any further developments. But to see something like this happen for a third time could raise some definite red flags.