Mets activate Sean Manaea, option Austin Warren

The Mets have reinstated Sean Manaea from the 60-day injured list ahead of this afternoon’s game against the Royals in Kansas City. Manaea will make his season debut this afternoon piggybacking Clay Holmes in relief as the Mets close out the first half. Manaea has missed the entire first half of the season rehabbing a right oblique strain he suffered in spring training. He suffered a setback late in his rehab when a loose body in his elbow was causing him discomfort, which he will attempt to pitch through.

After pitching to a 3.47 ERA in 181 2⁄3 regular season innings and starting four games in the postseason for the Mets, the 33-year-old lefty inked a three-year, $75 million deal to return…