Tyler Clippard was one of the Mets' several trade deadline additions last July, and the then-30-year-old pitched well for the team for the rest of the regular season before struggling in the playoffs. In 32.1 innings in the regular season, he had a 3.06 ERA, but in the playoffs, he had a 6.75 ERA in 6.2 innings. He'll probably be remembered more for the latter, whether or not that's fair.
Back in 2007, Clippard made his major league debut at Shea Stadium as a starting pitcher for the Yankees. He was traded to the Nationals following that season, though, and stuck there for several years as he developed into a very good major league reliever. Following the 2014 season, after seven years in Washington with a 2.68 ERA, he was traded to the Athletics for Yunel Escobar, and it was the A's that traded him to the Mets in July for minor league pitcher Casey Meisner.
Since the end of the season, Clippard has signed a two-year contract with the Diamondbacks. His brief time with the Mets went exceptionally well in the early going. Over his first 19.2 innings, he had a 0.46 ERA and lowered his ERA for the season from 2.79 to 2.01 in the process. But he had a few rough outings and a 7.11 ERA in total over his final twelve appearances in the regular season.