LOS ANGELES — In a Mets season defined by unanticipated pitching woes, Zack Wheeler was the steadiest starter over the first two months. It was an unexpected development because Wheeler had missed the previous two seasons after elbow and forearm operations.

So when he seemed to hit an abrupt wall over his past two starts, allowing 15 runs over three and two-thirds innings, Wheeler’s health became a focus.

The Mets and Wheeler insisted this week that he was physically fine, but on Wednesday afternoon the Mets placed him on the 10-day disabled list with right biceps tendinitis. Wheeler admitted that the tendinitis had been there for a couple of weeks, even when he had pitched well.

“But it’s kind of got a little worse, so I spoke up,” Wheeler said, hours before tempers flared in the Mets’ 8-2 loss, their third straight, to the Los Angeles Dodgers on Wednesday night.