Roessler, 57, joined the Mets' staff alongside Long in 2015, after serving with him for eight seasons in the Yankees' organization. Together, the two men preached elements of the launch-angle revolution that has swept across baseball. They urged Murphy to lift the ball more frequently to his pull side, resulting in the two best seasons of his career. To Cespedes, they preached patience, shrinking the free-swinging outfielder's strike zone.
Under Long and Roessler, the Mets went from tied for 21st to tied for 18th in the Majors in runs scored from 2014-17, from 22nd to 18th in on-base percentage and from 20th to tied for seventh in home runs.
Long, whose contract expired Wednesday, interviewed last month -- and was considered a favorite -- for the Mets' managerial job that went to Mickey Callaway. When general manager Sandy Alderson chose Callaway instead, Long began talking to other teams. He interviewed for the Nationals' managerial vacancy and is reportedly a candidate to return to the Yankees' staff in some capacity.
As hitting coach, Roessler will continue preaching many of the same principles that Long espoused.
Alderson previously revealed that bench coach Dick Scott is unlikely to return to the staff, and that Dan Warthen will not return as pitching coach. As such, the Mets must fill those positions, along with first-base coach and assistant hitting coach, Roessler's old post. A source said that bullpen coach Ricky Bones will sign a new deal to return to the same role. Third-base coach Glenn Sherlock remains under contract and will return.
It is unclear how much influence Callaway will have in filling the vacancies. Multiple reports Wednesday evening indicated the Mets were closing in on hiring Dave Eiland, who was teammates with Callaway on the 1999 Rays as their pitching coach.
Anthony DiComo has covered the Mets for MLB.com since 2008. Follow him on Twitter @AnthonyDiComo and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.