Mets place T.J. Rivera on DL with partially torn UCL in right elbow

SEATTLE — T.J. Rivera has worked hard to show that he has a good enough glove to go along with the bat that has brought him to the big leagues. But the infielder suffered a setback Friday, when the Mets placed him on the disabled list with a partially torn ulnar collateral ligament in his right elbow.

Rivera received a PRP injection to speed up healing, but without improvement in the next few weeks, the injury might mean surgery that would end his season.

“I know the injury he has certainly can be troublesome,” Terry Collins said. “So we’ll just see how it comes, and we’ll get him back doing some baseball activities. And we’ll see where we’re at.”

Collins likened Rivera’s injury to one suffered by Juan Lagares, who has avoided elbow surgery despite a partially torn ligament. Rivera is hitting .290, but elbow pain has kept him out of the starting lineup recently.

In other roster moves, Neil Walker (hamstring) and Brandon Nimmo (partially collapsed lung) were activated. Tyler Pill was optioned to Triple-A Las Vegas.

Happy homecoming

Michael Conforto grew up 20 minutes from Seattle and spent part of his childhood at Safeco Field, falling in love with baseball while watching the Mariners. Conforto was in his first game near his hometown as a big-leaguer.

“I’m going to enjoy it for these next three days,” said Conforto, who left about 30 tickets. He gave them something to cheer about with solo homers in the third and eighth innings.

Flores now, Smith later

Wilmer Flores will serve as the primary first baseman, but that tenure might not last long. Team officials intend to promote prospect Dominic Smith sometime after Monday’s non-waiver trade deadline.